Michigan senior receiver Roy Roundtree is recovering from minor knee surgery. He is expected to rejoin the team in two weeks -- just in time for the Alabama game.

Melanie Maxwell | AnnArbor.com

The graduation of top receiver Junior Hemingway and dismissal of projected starter Darryl Stonum have accentuated the senior's importance this year.

And now, leading up to the nation's most-anticipated opener, he's not there.

Roundtree had arthroscopic knee surgery Friday and is not expected to return to practice until the week of the season opener against Alabama.

"It's a little concerning," coordinator Al Borges said before Tuesday's practice. "Not him, so much. If it was a guy who hadn't played much, that would be a lot more disconcerting. But Roy's played so much.

"But when a guy hasn't practiced, there's always a certain amount of doubt, probably in his mind -- particularly his first game back. You got to get your sea legs back."

Arthroscopic knee surgery typically is a minor procedure with a quick rebound time. Coach Brady Hoke and receivers coach Jeff Hecklinski both said they expect Roundtree to play against the Crimson Tide.

But there's no guarantee he will be at full health, or conditioning, by Sept. 1.

Roundtree's absence is confounded by the uncertainty of starting tailback Fitz Toussaint, who was suspended following an offseason drunken-driving arrest. He began practicing Monday, after missing seven workouts, but his status for the opener is uncertain.

It's quite the turn of events for a Michigan team that, facing significant turnover along the lines, was expected to rely on its wealth of experience at the skill positions.

Now, two of the offense's three most significant skill-position players are clouded in uncertainty -- with the defending national champion Crimson Tide, and their reigning No. 1 defense, on deck.

"It's just next guy up -- and not to be callous about Roy being injured, because he's a valuable entity, but you just can't think that way," Borges said. "Next guy up, and we got several guys playing the position."

Easier said than done.

Roundtree posted just 19 catches last year, but still has 123 career receptions for 1,724 yards and 12 touchdowns. The rest of the Michigan receivers combine for 52 catches, 717 yards and six touchdowns -- less than half his production.

Only three other wideouts have even caught a pass: juniors Jeremy Gallon, Drew Dileo and Jeremy Jackson.

The leading candidates for the third starting receiver spot -- sophomore Jerald Robinson and freshmen Amara Darboh and Jehu Chesson -- combine for zero.

Who is practicing at Roundtree's flanker position? And more importantly, who plays for him should he miss game time?

Borges said "all" the big-bodied wideouts are candidates, but singled out Robinson for being particularly impressive.

"He's certainly a candidate, without a doubt," Borges said. "He's fired up and ready to make a contribution. And from what I've seen, I think he's going to do that.

"He's good at catching the ball, running after the catch, taking jump balls. He plays the position a little like Junior plays it, and he's faster than you think he is. He possesses all those skills that it takes to play wide receiver. Now he's just got to show off his game, do all the little things well."

Darboh, a 6-2 freshman, also has impressed in camp -- Roundtree is among those who have noticed -- and could factor into the equation. Chesson, a 6-3 freshman, is another.

Jackson, a 6-3 junior with seven career catches, was mentioned by Borges as yet another possibility.

The wild card could be junior quarterback Devin Gardner, who has played receiver part time since the spring. He is splitting his snaps about 50-50 between the two positions, and has drawn rave reviews from teammates for his athleticism.

"When he gets out to receiver, you think he's a receiver," quarterback Denard Robinson said. "He looks like he's been playing there for years."

Robinson struggled with his accuracy in the passing game last year, completing only 55 percent of his passes and tossing a Big Ten-worst 15 interceptions.

Now he's lost his favorite target from last year, Hemingway. That makes the return of Roundtree -- the man he's hooked up with more than anyone else in his career -- all the more important.

Kyle Meinke covers Michigan football for AnnArbor.com. He can be reached at 734-623-2588, by email at kylemeinke@annarbor.com and followed on Twitter @kmeinke.