The Pac-12 has been ferocious to begin the season, particularly from a Fantasy perspective. The analysis starts with the high-powered Oregon Ducks, who need no introduction. The loss of Chip Kelly has done nothing to slow the up-tempo offense, as quarterback Marcus Mariota has shredded opposing defenses thus far in 2013. However, the most productive quarterback in the country might be Oregon State gunslinger Sean Mannion. Mannion has passed for an astounding 2,018 yards and 21 touchdowns through five games. He tore up Colorado on Saturday for six touchdowns and has tossed just two interceptions this season. Not surprisingly then, the nation's leading receiver also resides in Corvallis, as Brandin Cooks has 52 catches for 807 yards and nine touchdowns.

Meanwhile, the Washington Huskies feature one of the best rushers you've never heard of in Bishop Sankey. The 5-foot-10 junior is fifth in the nation in rushing with 607 yards, while scoring in each of U-Dub's first four games. UCLS's Brett Hundley has been dynamite as a dual-threat option at quarterback through three games for the Bruins. And let's not forget about the efficient Stanford offense led by Kevin Hogan.

Who else is on the rise, and whose stock has taken a tumble? Let's take a peek in this week's College Football Barometer.

UPGRADE

Marion Grice, RB, Arizona State: The all-purpose senior running back has shown superior versatility this season. Grice has scored eight touchdowns on the ground through four games, toting the pigskin at least 12 times in each of those contests. He has also shown excellent hands out of the backfield, collecting 22 catches for 183 yards and four more scores. Grice clearly has a nose for the end zone; he scored 19 touchdowns in 2012. He might not be the most explosive back, but his ability to find the promised land makes him extremely valuable.

Dorial Green-Beckham, WR, Missouri: DGB is living up to the hype in his second campaign with the Tigers. The 6-6 wideout broke 100 receiving yards for the first time in his career on Sept. 21 at Indiana then scored twice in Saturday's contest with Arkansas State. Green-Beckham has found the end zone four times in his last three games, becoming the favorite target of experienced quarterback James Franklin. DGB has been able to use his size and speed to average 15.9 yards per catch through the first four games of the season. The sophomore should continue to hold his own, even as Mizzou heads into a daunting SEC stretch.

Rashad Greene, WR, Florida State: Consistency has been the hallmark of Greene's career at Florida State. He has caught at least one pass in 19 straight games, while hauling in at least one touchdown in each of the last five tilts. Greene hasn't missed a beat despite the quarterback change from EJ Manuel to Jameis Winston; the latter has found Greene for five touchdowns through four games in 2013. By comparison, the rest of the team has seven receiving touchdowns. Greene has clearly emerged as a favorite target of Winston's particularly in the red zone. Greene should continue to find success as Winston's go-to receiver.

Cody Fajardo, QB, Nevada: Fajardo missed two games due to a knee injury, but came back with a vengeance against Air Force on Saturday. The junior quarterback completed 38-of-54 passes for 389 yards and three touchdowns, adding 81 yards and two touchdowns on 11 rushes. The dual-threat quarterback had 2,786 yards and 20 passing touchdowns in 2012, while rushing for 1,121 yards and 12 scores as well. He briefly left Saturday's tilt after getting kicked in the knee, but made his way back for by far his best output of the season. As long as he's healthy, Fajardo is a Fantasy dynamo.

CHECK STATUS

Todd Gurley, RB, Georgia: Gurley is listed as day-to-day with an ankle injury. He was forced to leave Saturday's victory over LSU after just eight carries due to the injury. He had already produced 73 yards on those rushes, too. The sophomore is one of the nation's top running backs, rushing 71 times for 450 yards and four touchdowns for the 3-1 Bulldogs. Keith Marshall would see more work in Gurley's absence. Marshall is no slouch himself; the sophomore backfield mate of Gurley's has 213 yards rushing, 111 yards receiving and two total touchdowns this year. With what should be a victory over Tennessee on Saturday looming, the Bulldogs may choose to rest Gurley to keep him healthy for the rest of their SEC slate.

Melvin Gordon, RB, Wisconsin: Gordon suffered a left leg injury in Saturday's 31-24 loss to Ohio State. As a result, Gordon produced a season-low 74 yards rushing and did not find the end zone for the first game this season. More significantly for the Badgers, though, is the possibility that Gordon could miss more time. Gordon has been a beast for Wisconsin this season, averaging 10.3 yards per rush en route to 698 yards through five contests. James White is a more than capable backup, but Gordon has been the unquestioned breakout star for the Badgers in 2013. On the bright side, Gordon will have two weeks to recover; the Badgers play host to Northwestern on Oct. 12.

Stephen Morris, QB, Miami: Morris reinjured his ankle at USF on Saturday and was forced to exit the contest in the second quarter. The senior quarterback wasn't needed in the 49-14 rout anyway, accumulating 222 yards passing and two touchdowns in less than one half. Still, it remains to be seen if Morris will be bothered by the ankle. His health will be of vital importance as the undefeated Canes head into ACC play. Morris has not played a full game since Sept. 7 against the Florida Gators.

Venric Mark, RB, Northwestern: Mark rushed for 1,366 yards and 12 touchdowns last season, but has barely been able to stay on the field in 2013. He has rushed just 11 times for 29 yards, all coming in the Wildcats' opener at California. Mark has been battling an undisclosed "lower body" injury since August and has missed Northwestern's last two games. The Wildcats are coming of a bye week, and Mark is expected to play in the Big Ten opener; however, he will face a tall task against the undefeated Ohio State Buckeyes. Mark may also be eased into action with the success of Treyvon Green and Mike Trumpy to begin the year. Mark has plenty of upside, but Fantasy owners may not reap the rewards of his return immediately.

DOWNGRADE

De'Anthony Thomas, RB, Oregon: Thomas hurt his right ankle on the opening kickoff against Cal on Saturday, and his status for Oregon's next game versus Colorado is uncertain. A home-run threat every time he touches the ball, Anthony has rushed 42 times for 338 yards and six touchdowns for the Ducks. He hasn't been as involved in the passing game this season, though; Thomas has just three grabs for 58 yards. He caught 45 passes for 445 yards and five touchdowns out of the backfield in 2012. Still, Thomas is a game-breaker who will be tough to replace if he can't go against the Buffaloes. Monitor his progress during the week.

Connor Shaw, QB, South Carolina: Shaw sprained his shoulder at UCF on Saturday and will miss the next 2-3 weeks for the Gamecocks. Shaw has battled injuries, including foot and shoulder issues in 2012. The dual-threat quarterback will be replaced by Dylan Thompson, who has some experience at the helm for South Carolina. Thompson tossed 10 touchdowns and just two interceptions in relief of Shaw last season, passing for 1,027 yards in the process. He has also scored three times thus far in 2013. The Gamecocks offense should be fine, but Shaw will only be a spectator for the short term.

Marqise Lee, WR, USC: Lee suffered a knee injury in the fourth quarter of Saturday's loss to Arizona State. He has been diagnosed with a severe knee sprain. Lee hadn't exactly been lighting it up before the injury either, struggling to get his footing due to subpar quarterback play for the Trojans. Lee had 30 catches for 385 yards and a touchdown through five games before the injury. By contrast, Lee hauled in 118 passes for 1,721 yards and 14 touchdowns with Matt Barkley under center just a season ago. Still, it's another crushing blow for the disheveled Trojans; it looks like the Trojans will be missing more than just recently fired coach Lane Kiffin when they take on Arizona in their next contest on Oct. 10.

Tommy Rees, QB, Notre Dame: In reality, Rees shouldn't even be the starting quarterback for the Fighting Irish. Notre Dame went to the national championship game last season with Everett Golson, who was a freshman at the time, under center. However, Golson was kicked off the team due to academic issues, leaving Rees to fill the void. He started the season hot, but has struggled over his last two games. Rees has completed a putrid 39.7 percent of his passes over his last two contests, including tossing three interceptions in Saturday's loss to Oklahoma. Rees didn't break 150 yards passing in either of those tilts. Coach Brian Kelly has indicated he will stick with Rees against Arizona State, but his days could be numbered as the starting quarterback for the Fighting Irish.