COLUMBIA, Mo. (AP) -- Aldon Smith's bad break was Brad Madison's big break.
Madison had three sacks last week, keeping the pass rush humming for No. 18 Missouri.
Smith set a school record with 11.5 sacks as a freshman and is expected back for a matchup of unbeatens Saturday night when the Tigers (6-0, 2-0) take on No. 3 Oklahoma (6-0, 2-0). Madison had three sacks last week at Texas A&M and is among the conference leaders with four sacks on the year.
"It certainly hurts us as a defense to have a guy like Aldon not be out there," Madison said. "I knew guys like myself would have to step up and contribute, and we've done that so far.
"It's just going to make us stronger when he gets back."
Madison arrived at Missouri as a heralded offensive lineman from South Harrison High School in Bethany. His older brother, Ryan, who was a three-year starter at guard for the Tigers from 2006-08.
He devoted a redshirt season to establishing himself and working on blocking technique, but struggled putting on weight and approached coach Gary Pinkel about making the switch from protecting quarterbacks to chasing after them.
"We were watching him move as an offensive lineman in practice and we knew that we were going to have to put about 40 pounds on him," Pinkel said. "He showed some speed and quickness and we decided to give him a shot, and the rest is history."
The position switch is anything but normal.
"I'm going to suggest to you that there are very few times you recruit an offensive lineman and move him to defensive end," he said. "If that happened regularly, I think there would probably be someone else standing here."
Madison's all-around athleticism has enabled him to progress quickly on the defensive side of the ball. He was a state champion shot putter in high school, finished second in the discus, and starred on the basketball team, too.
Teammates figured once Madison developed technique and became comfortable in the system, he could be a contributor.
"Now that he's more consistent with his game, we know what an asset he is to our defense," Smith said. "He's always shown that spark that he could be really good, and now he's getting his chance to show what a great player he really is."
Missouri's defense has allowed only 10.8 points per game, second best in the country, heading into its toughest test against a Sooners team ranked No. 1 in the BCS. Pinkel said it's because players understand the team concept, but dodged a question whether it had the potential to be his best at Missouri.
"You don't pass trophies out halfway into the season," Pinkel said. "When Saturday's over, everybody will draw some concussions, one way or the other.
"I think you earn that, you earn respect like that. But I don't think you do it over a game, you do it over an entire season."
Missouri will have to plug in another substitute this week with linebacker Luke Lambert likely to miss two games with a knee strain.
Whether Smith is back or not, the Tigers approach the game with confidence.
"We've had guys go down and guys step in each week and I'm proud of what we have done as a defense," Madison said. "One of our advantages is our depth.
"When someone goes down, we know someone can step in and we'll be just as good."