Long snapper Jon Condo practiced Friday for the first time since suffering a concussion Monday night in the second quarter against San Diego.

Condo said he has passed two post-concussion tests and will have to pass two more in order to be cleared for Sunday’s game at Miami.

“It’s a process,” Condo said. “I’m making the trip, and that’s really all I know.”

Condo, who was listed as questionable for Sunday’s game, was injured while covering a punt against the Chargers.

“From what I saw from film, it was a knee to the back of the head. (Tight end) Brandon Myers, friendly fire. That’s all I could tell on the film. I saw the knee to the back of the head and then my face going into the dirt. I don’t know what one it was that got me.”

Practice squad long snapper Nick Guess will travel with the team to Miami, too. If Condo can’t play, then Guess will be signed to the 53-man roster and fill in against the Dolphins.

Wisniewski working first team: Stefen Wisniewski continued taking most of the first-team snaps at center, and coach Dennis Allen said he will “probably” start against Miami.

Alex Parsons started Monday night against San Diego, in large part because Wisniewski missed most of training camp with a calf injury. What’s more, Parsons is now battling a shoulder injury.

“I think the coaches handled it (correctly),” Wisniewski said. “They felt I wasn’t quite ready. I felt healthy but I had missed a lot of reps, so it made sense that they did that. I feel great now. I got a lot of reps this week. I’m feeling healthy and feeling ready to go.”

Battle of the backups: After catching 13 passes and rushing 15 times against San Diego, Raiders running back Darren McFadden is on pace to touch the ball 448 times this season.

Raiders coach Dennis Allen and offensive coordinator Greg Knapp both said that would be too much work for their No. 1 offensive weapon, who missed nine games last season with a sprained foot. They’ll likely give McFadden a few more breaks Sunday. The question is, which backup running back will get more snaps, Taiwan Jones or Mike Goodson?

Allen said that battle between Jones and Goodson that began in OTAs and continued in training camp has yet to be decided.

Jones is listed on the unofficial depth chart as McFadden’s primary backup, but he had a rough game Monday night, muffing a kickoff then having trouble fielding a pitch, albeit high, from fullback Marcel Reece on a reverse. The Raiders lost 25 yards on that play, and Jones never touched the ball again at running back.

“Ball security is very important to us, and to have two balls on the ground, whether it was a high pitch or the kickoff was unique, we got to have great ball security,” Knapp said. “It wins and loses games. That’s one of the things we’ve stressed from Day 1 to the team. So that was an issue in the game. He’s got to build some confidence back.”

Goodson suffered a scary neck injury during training camp and had a rough preseason debut at Arizona, fumbling twice and suffering a stinger. But he carried twice for 13 yards against San Diego, and Knapp said Goodson has regained his confidence.

“He’s much more confident now and you can see it on the field,” Knapp said. “He’s cutting, making moves now to where he’s feeling back to what he was before, 100 percent. It took a little bit longer to come back, because it was a very dramatic hit, but he’s back to full strength now.”

Extra points: WR Jacoby Ford, who underwent surgery on his left foot, and CB Ron Bartell, who has a broken left shoulder blade, are the only Raiders ruled out for Sunday’s game. WR Juron Criner (ankle), Parsons (shoulder), Condo (concussion), RB Taiwan Jones (ribs) and LB Rolando McClain (ankle) are questionable.

Follow Raiders reporter Eric Gilmore on Twitter: @CBSRaiders.