EDEN PRAIRIE, Minn. -- Toby Gerhart has waited behind Adrian Peterson for his chances for four seasons, watching as Peterson has recovered from injuries unlike anyone in the NFL and getting the occasional opportunity as Peterson's backup.
So Gerhart was not surprised at all when Peterson returned to practice Friday for the Minnesota Vikings, after spraining his right foot in last week's game and spending two days in a walking boot earlier this week.
"No, he's Superman," Gerhart said. "As long as there's not any kryptonite I think he'll be alright. He's amazing. I think everybody was surprised to see him out there and he looked good."
Peterson returned to practice Friday after being held out Wednesday and Thursday and restricted to work in the pool. Gerhart, dealing with a hamstring injury, also returned to practice for the first time this week and Minnesota's top two running backs are listed as questionable for Sunday's home game against the Philadelphia Eagles.
Peterson and coach Leslie Frazier are making no promises regarding the MVP running back's availability for Sunday's game, but both were encouraged after he returned to practice. He was a limited participant in Friday's practice and demonstrated some of the moves Frazier was hoping to see.
"It was impressive when you consider the early diagnosis," Frazier said. "So he's unique, very unique."
Even Peterson, well-known for his recuperative powers and ability to play through injuries, was surprised by how he felt on Friday. The league's second-leading rusher has also played through groin and hamstring injuries this season.
"I feel pretty confident," Peterson said. "I feel pretty good. I'm excited I feel the way I do, based off the injury and the time I've had to kind of rejuvenate that body and rehab the foot to get the strength back."
Cornerback Chris Cook, added to the injury report for the first time with a knee injury, was limited Friday and is questionable for Sunday. Tight end John Carlson hasn't passed concussion testing and will miss Sunday's game. Cornerback Josh Robinson hasn't been able to return to practice yet from a fractured sternum on Nov. 17 and is out for Sunday. Cornerback Xavier Rhodes (sprained ankle) and right guard Brandon Fusco (knee sprain) are listed as doubtful.
Frazier said the availability of Peterson, Gerhart, Fusco and Rhodes won't be determined until the weekend.
Peterson underwent several tests on the injury he suffered when Baltimore linebacker Arthur Brown landed on his foot in last week's game. He had X-rays, a magnetic resonance imaging test and a CT scan to rule out any bone breaks or serious ligament damage in the foot.
Peterson, second in the league in rushing to Philadelphia's LeSean McCoy, said the work in the pool was beneficial. He said he would "leave that open" when asked if he could play if the game was today.
"I would probably say just planting," Peterson said about the most difficult part of dealing with the injury. "I've been kind of testing it out as far as putting weight on it all week. It's pain there, but it's at the point where you have to suck some of the pain up. As far as me trying the putting pressure on it, the pain that I do feel I'm able to take that. It's a different force when you're out there running and planting and really being explosive."
Peterson will talk to Frazier and the team's medical staff this weekend to determine his status.
"We've been down this road before where we've had to work him out day of a game," Frazier said of the negotiating that goes on with Peterson. "He's amazing when it comes to recovering from injuries. He's so different. He doesn't like to sit. He believes he's more than capable of getting out there and he'll let you know, but we'll see what happens. We'll see how he feels tomorrow."
As for the groin injury that he's been dealing with for more than a month, Peterson said: "It's nothing that I'm concerned about. Is it fully healed? No. But I'm not worried about it at all."
Though the Vikings (3-9-1) are officially eliminated for the season, Peterson hasn't given any thought to just holding himself out.
"Not at all, man," Peterson said. "That's just not my mentality, leaving these guys out to dry, just because, what the heck, my passion for the game. I love the game too much to sit out just because. If I'm out, you're going to know that he can't go."
Gerhart has become a bigger part of the offense over the past month with Peterson limited because of the groin injury. Gerhart said he suffered the right hamstring strain on a 41-yard touchdown in Sunday's game after breaking a tackle. He was limited in practice Friday too, but didn't try to "burst."
"Everything he did stride-wise was good, did a good job cutting, did all the things you'd want to see with the exception of the burst," Frazier said. "That will be the next step."
Gerhart said he felt "pretty good" Friday.
"We tested it and we'll see how it goes," Gerhart said. "It's feeling alright."
The Vikings could be without their top three cornerbacks on Sunday depending on Cook and Rhodes' status. Rhodes hasn't practiced all week after suffering the sprained ankle in Sunday's game.
"We've been thin there for a while," Frazier said. "Xavier's really been playing well for us. That will be a loss, but that gives some other guys opportunity to step up and play more, and we're going to need them to play well. They've got some good receivers that are playing really well for them and their quarterback is playing well also. So, gives some other guys some opportunities."
Without Rhodes, Marcus Sherels would likely slide into a starting role. Robert Blanton, who has played nickel back the past few weeks, would likely be the third corner, if Cook can play. Without Cook, it could lead to more time for Blanton at cornerback and possibly Shaun Prater, who was claimed off waivers Oct. 23.
Frazier said Blanton has been practicing at times as an outside cornerback.
"When you're getting as thin as we are, everybody's a candidate to be moved around and playing chess with," Frazier said. "So, you don't rule out any possibilities at this point. We are pretty thin."