Here's what you can expect from Jared Goff in his first NFL start for the Rams

It took forever -- nine games of Case Keenum, to be exact -- but the Jared Goff era is just about ready to get underway in Los Angeles.

Boy, did those nine games take their sweet time. Keenum accumulated a 76.8 passer rating and threw two more interceptions than touchdowns, the Rams averaged 15.4 points per game, and they even won two games without scoring a touchdown. Meanwhile, Goff mastered the Microsoft tablet and became a skilled camera man.

Fisher celebrated each and every game by repeatedly telling reporters that Keenum was his starting quarterback, because if there's something Fisher loves more than going 7-9, it's going 7-9 with a perpetually awful quarterback. But that changed this week.

Goff, the No. 1 overall pick in this year's draft, will start for the Rams at home against the Dolphins, which is both good and bad news for Kenny Britt.

Unfortunately for Goff, Ryan Tannehill won't be giving him any advice ahead of the game.

That's probably good news for Goff considering Tannehill posted a 39.0 passer rating in his first start.

There's really no way to know how Goff will perform. The last time he started in a meaningful game, he led Cal to a win in the Armed Forces Bowl in December 2015. He did play in all four of the Rams' preseason games and attempted 49 passes, but that's the preseason and it was at the very beginning of his career, when he clearly wasn't NFL ready.

Luckily, I covered Goff as a Daily Californian football beat writer for the first two years of his college career and wrote about him for CBS Sports in his final season. So, let's try to answer that question: What can we expect from Goff on Sunday?

His strengths and weaknesses

Note: For a complete picture of Goff's college career, read this CBS Sports story. Most of the quotes and nuggets in this section are taken from it.

Goff was drafted first overall -- nay, the Rams felt the need to mortgage their future for him -- because he didn't really have any real weaknesses in college. He was solid in just about everything. His biggest strengths were his accuracy, timing, and footwork within the pocket. Let's start with his accuracy.

In three years at Cal, Goff completed 62.3 percent of his passes. Keep in mind, he threw the ball a ton: 42.38 passes per game. It's also important to note that his completion percentage improved each season.

• 2013: 60.4 percent
• 2014: 62.1 percent
• 2015: 64.5 percent

He was particularly accurate on fades -- one of the most frequent plays Cal ran in the red zone and, well, anywhere on the field. On those passes, Goff displayed the necessary touch and precision to place the football into pockets only his receivers could reach deep down the field.

Here's one example:

That's Kenny Lawler coming down with the pass. Here's what he told me about those sort of passes last September.

"People think I make it look easy," Lawler said. "But, man, it's really easy because of Goff. We have our timing down and he knows exactly where the ball needs to be at the exact right time."

Timing is the other aspect his Cal teammates raved about. For that, Goff can credit his footwork.

At least that's what his offensive coordinator, Tony Franklin (now at Middle Tennessee State), told me last year, comparing Goff's quick feet to Peyton Manning's.

"Manning will move from the A gap to the C gap feet -- feet hot, hot all the time, typing all the time. He can throw the ball back across the field because his body position is perfect," Franklin said. "Guys who step have to wait until the foot lands before they can throw the ball."

Take a look:

Goff will need that footwork behind an offensive line that's allowed 23 sacks -- the 10th-most in the NFL.

Goff's weaknesses are more about hypotheticals than actual bad traits he developed in college. He played in a sibling of the Air Raid, so he handled pretty much every snap out of the shotgun alongside three or four receivers. They didn't huddle. Most of his reads were pre-snap, as he had to determine whether to hand the ball off or throw it.

Here's how I described the offense in that article last year:

At the core of the offense are nine passing concepts, five or six screen concepts and five or six running concepts.

"When you learn the concept, you understand the word," Franklin says. "So when you say 'sluggo,' immediately your brain says 'OK, sluggo means this. It means my eyes start here, there's a player going there and I'm bam, bam, bam, one, two, three.' So most of us, within a two-week period, can learn those concepts, they can master that in their brain."

The point being, mastering an NFL offense will be a completely different challenge for Goff, which is probably why he's been standing on the sidelines until now. Goff's biggest weakness is that he had to transition out of a system that doesn't exist in the NFL.

"I remember watching him in training camp and OTAs," Rams receiver Pharoh Cooper told the OC Register. "He couldn't even name the play in the huddle. Now, he's out there, calling it out there fast. He's learning his checks and reads. Just looking a lot more confident."

We'll find out Sunday if he successfully made that switch. It didn't come to him immediately, evidenced by his poor preseason.

What he showed in the preseason

In four preseason games, Goff went 22 of 49 (44.9 percent) for 232 yards (4.7 yards per pass), two touchdowns, two picks, and a 55.8 passer rating. He also fumbled three times. All of those traits I described above disappeared.

He was not ready for the NFL, even though he spent most of his time playing against (and with, to be fair) backups. That much was clear when I went back to watch all of his passes in the preseason.

Most of the time, he threw short and quick timing routes. According to Pro Football Focus, he attempted two deep balls in the entire preseason.

Out-routes were common. So, the Broncos began jumping them.

He also had some issues reading and diagnosing defenses. Take his interception from his first preseason game.

The Cowboys showed double a-gap pressure before the snap, but at the onset of the play, one linebacker dropped into the coverage while the other delayed his blitz. Meanwhile, another blitzer emerged off to the side.

The issue was how long Goff held onto the ball. The Cowboys showed blitz, blitzed, and Goff was still oblivious to the incoming hit.

He did, however, experience a few good moments. Later in his preseason debut, he diagnosed the Cowboys' coverage, knew that he'd have the middle of the field open with both safeties shadowing the outside, and hit his receiver for what should've been a gain of 30 or so yards to the 5-yard line.

The pass was jarred loose by a defender.

The one critique of the play is that it took Goff a split second too long to release the football. If he threw the pass a bit earlier, that kind of hit wouldn't have disrupted the catch. That'll come with time, though.

My favorite play came against the Broncos. It won't go down as anything more than a completion in the middle part of the field, but it represented Goff's ability to hang in the pocket, step up, and throw a perfect pass.

Goff's receiver wasn't really open, but he recognized the defender had his back turned. So, Goff threw the ball directly above the defensive back's head. He threw his man open.

But those kinds of plays didn't happen enough in the preseason. That's why Goff started the year behind Keenum and even Sean Mannion on the depth chart. The glimpses were nothing more than brief flashes of potential. He looked like, well, a rookie who came from a college system. And that lone weakness was enough to take away from the positive parts of his game.

He didn't look like the quarterback the Rams drafted. There's no way around that.

How he can help the Rams offense

So here's the thing about Goff's debut: He's taking over an already awful offense. Goff is inheriting an offense that's last in points scored per game, second to last in yards gained per game, and third to last overall using Football Outsiders' more advanced metrics. It's a remarkably unremarkable offense that's managed to render Todd Gurley useless.

That's not entirely on the coaching and scheme, it's also on the players. They don't have three adequate receivers. Kenny Britt, Brian Quick, and Tavon Austin are almost always the three receivers they use when they roll out 11 personnel on 59 percent of their snaps, which is exactly league average (per PFF).

Fun fact about Austin: According to PFF, the Rams have called 12 reverses/end arounds/jet sweeps for him this season. Those 12 plays have gained, in total, 51 yards. Only once, has Austin gained more than 10 yards.

In college, Goff worked with a committee of receivers. All of them were good. Despite the fact that not too many people around the nation knew about those receivers, most of them ended up earning spots at the next level. The point being, even Goff's third, fourth, and fifth receivers are playing in the NFL. Without being drafted -- Trevor Davis was the only one who didn't go undrafted -- they managed to stick around at the highest level.

An argument can be made that those receivers elevated Goff's level of play. An argument cannot be made that the Rams' receivers will elevate Goff. He'll be forced to carry them. I don't think he'll be able to do that -- at least not immediately.

There are a few reasons, though, to believe he can improve the Rams offense. With Keenum as their quarterback, the Rams basically had no shot to do any damage when their line allowed pressure. Keenum posted a league-low 38.1 passer rating when under duress, according to PFF. And Goff performed well under pressure in college. Per PFF, Goff was under pressure on 172 dropbacks in his final season at Cal -- the ninth-most in the entire FBS. He still managed to put up prolific numbers.

Another reason is Goff's efficiency in the red zone. The Rams are ranked 29th in red zone efficiency. In his sophomore and junior seasons, Cal scored a touchdown on 68 percent of their red zone trips. The Rams' touchdown percentage this year is 42.86 percent.

Even during his poor preseason, he demonstrated the ability to be precise when the field shrinks. Both of his touchdowns came in the red zone.

If Goff can improve the Rams' red zone efficiency, he might just wrestle away the team MVP award from the Rams' punter.

Don't have high expectations

Goff might be the Rams' savior, but don't expect him to light up a Dolphins defense that isn't terrible. Most rookie quarterbacks struggle in their debuts -- even No. 1 overall picks.

My best guess is that the Rams will call a conservative game by letting Gurley run into a stacked box and using shorter, quicker passes to make Goff's life easier. If the Rams win this game, they'll need to pull off the kind of defensive performance that allows the offense to stick with that conservative approach, which won't force Goff to make difficult throws. The Rams will also need to protect Goff in his first start, which might be difficult seeing that the Dolphins have notched 12 sacks in their past four games -- all of which were wins.

If the Rams do air it out, I'd expect to see Goff show off better accuracy than Keenum. And if the Rams do drive down the field, look for Goff to connect with the 6-foot-3 Britt. He's caught three touchdowns this year and all have been from within 20 yards of the end zone.

But, again, we just don't know how the Rams' offense will change with Goff under center. The Rams might run an entirely different offense now that they have a new quarterback.

Adam Gase is clearly confused, because there just isn't much the Dolphins can do to prepare.

"You don't know what to tell your guys as far as, 'Here's what he does well. Here's what he struggles with. Is there anything we can take advantage of?'" Gase said, per ESPN.com. "There are all those questions that a lot of times at least you can ask and give answers to. Right now, we have limited film. We can dig into the college scouting reports and pull up college tape and all that stuff, but really, you always want to go off of NFL tape."

Heck, even the Rams probably have no idea how Goff will fare. Here's the good news for them: He can't be any worse than Keenum -- probably.