ROSEMONT, Ill. - Luther Head came out of the Illinois locker room dragging his injured right leg behind him. He hobbled to a set of stairs he needed to climb to leave the Allstate Arena and grabbed the handrails on either side of the narrow staircase and pulled himself up two flights.

Handicappers think twice. This is Illinois’ best offensive player. Not its best player, but its best pure scorer.

Head’s hamstring really hurts. You could see it late in the Illinois victory over Wisconsin-Milwaukee here Thursday night and you could see it 90 minutes after the game as he left the building.

Slide show   March 27 See images from the wins by Michigan State and North Carolina on Day 8 of the NCAA Tournament.

All together Illini fans: “Uh oh.”

Head hurt the hamstring in practice Monday and this is not something you take two aspirin at bedtime and it’s gone in the morning. It will hurt until Illinois stops playing and Head can rest.

He can’t rest. If he does, Illinois’ stops playing.

One game from the Final Four, Illinois needs all its options. It needs its bigs to be a threat so its guards do not have to throw in a lot of 3-pointers to beat Arizona in the regional final on Saturday. It needs Head’s defense on Hassan Adams, so the physical Wildcat guard can’t go for 19 points — seven over his season average — like he did in the 79-78 victory over Oklahoma State.

Illinois showed the breadth of its options with five players in double figures in the 77-63 victory over the Panthers. The Illini shot 49 percent from the floor and committed just nine turnovers against a team that thrives on creating turnovers.

Head had the least to do with the win. He got 12 points on 5-of-15 shooting from the floor, but he managed just one rebound.

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Late in the first half, Head grimaced in pain under the basket and came to the bench. He angrily slapped the hand of coach Bruce Weber and took a seat.

“You have to just try and play through it,” Head said. “You just try to play through the pain.”

If it was Deron Williams hobbling out of the locker room, Illinois would be cooked right now. Williams is the team’s most valuable player, the rugged point guard who takes the ball where he wants on the floor and makes his teammates better.

Williams scored 21 points and had eight assists Thursday and he will need another big game on Saturday for Illinois to win. I don’t think Arizona guards Salim Stoudamire or Mustafa Shakur can handle him, so Williams could go for 25.

He might have to, which is the good thing about Illinois. It does what it has to in order to win. It can overcome Head’s injury as long as he can give something, anything, to the cause.