Despite missing his second consecutive day of practice because of a swollen left knee, Vikings linebacker E.J. Henderson said he feels "pretty confident" that he will be able to play in Sunday's home opener against the Tampa Bay Buccaneers.

Coach Leslie Frazier said it will be a "game-time" decision based on how Henderson performs during a pre-game workout at the Metrodome. The Vikings listed Henderson as "questionable," which means a 50 percent chance of playing.

Henderson said he had similar swelling and soreness in the knee during an early November game last year and was still able to play on Sunday.

"We pretty much had to do the same thing -- drain it, treat it and I made it out there Sunday," said Henderson, who had the knee drained on Thursday. "This is nothing out of the ordinary. Just maybe a little more swelling, a little more pain. But it's something that we're dealing with and hopefully, I'll be able to rock on Sunday."

Henderson said the swelling comes from where the metal rod was inserted during surgery for a broken femur during the 2009 season. X-rays were taken on the knee because the metal rod would affect the reading of a magnetic resonance imaging exam. Frazier said the X-rays revealed no structural damage.

If Henderson can't play, his younger brother, Erin, the team's starting weak-side linebacker, would move into the middle and probably make the play calls as well. Erin took reps there in training camp and the past two days. Kenny Onatolu, primarily a special teams player, would start at Erin's weak-side linebacker position if E.J. can't play.

Frazier said the team didn't give much thought to bringing in a linebacker from the outside. He said he's still "hopeful" that Henderson will be able to play. He also added that he has more confidence in the players he has than any outside player who is available.

All things considered -- talent, amount of reps (Henderson plays every snap) and the depth behind him -- E.J. Henderson is one of the starters the Vikings can least afford to miss.

Also on the Vikings' injury report: DE Adrian Awasom (knee) is questionable after limited participation in Friday's practice; CB Asher Allen (toe) and WR Michael Jenkins (groin) are probable after full participation.

For the Bucs: WR Sammie Stroughter (foot) and CB Myron Lewis (ankle) are out; backup LT James Lee (knee) is questionable after not practicing today. And DE Da'Quan Bowers (shoulder) is probable after limited participation. TE Kellen Winslow, who missed Wednesday and Thursday for non-injury reasons, was taking off the injury report after practicing Friday.

UPDATE: Vikings safety Eric Frampton was fined $15,000 for his horse collar tackle on special teams in Sunday's game at San Diego. CB Cedric Griffin wasn't fined for his late hit out of bounds.