Roy Roundtree, Carvin Johnson doubtful

Michigan could be missing two starters when it visits rival Notre Dame on Saturday.

Coach Rich Rodriguez said Monday that receiver Roy Roundtree is doubtful and safety-linebacker Carvin Johnson is "very doubtful" after suffering injuries in the opener against Connecticut.

Roundtree, who led Michigan with 32 receptions for 434 yards in 2009, has internal bruises after taking a big hit early in the third quarter.

Johnson sprained his knee and wore a brace after the game. Redshirt freshman Thomas Gordon or sophomore Floyd Simmons will step in for Johnson if he can't play, Rodriguez said.

Michigan already is down one starter in the secondary, as cornerback Troy Woolfolk likely will miss the season with an ankle injury.

"We're kind of hanging on in the secondary a little bit," Rodriguez said.

Michigan will issue its official injury report Thursday night.

Adam Rittenberg covers Big Ten football for ESPN.com. He can be reached at espnritt@gmail.com.