Purdue linebacker Sean Robinson plays through knee infection

• Central Michigan at Purdue%2C noon Saturday%2C ESPN News

WEST LAFAYETTE -- Sean Robinson's right leg was big.

No, really big.

"He's got some big legs to begin with," said Purdue tight end Justin Sinz, who is also Robinson's roommate. "Looked like he had a couple of bratwursts on his knee."

An infection nearly cost the fifth-year senior linebacker an opportunity to play in the season-opening victory over Western Michigan.

It wasn't until Saturday morning, after Duane Carlisle — the director of sports performance — put Robinson through an abbreviated workout that the Illinois native was confident he could contribute.

"That's as simple as it was. I came over here not knowing if I was going to play or not," said Robinson, who missed the team's 211 pregame session at Mackey Arena. "Friday night, I made my mind up if I could get to 50 percent or something just to get out there. If I can go a series and I can't do my assignment, then I can't do my assignment. Coach will see it and I'll know it and they'll play somebody else. I was well enough to do my assignment."

How did Robinson reach this point?

Initially, he thought the infection was caused by a bug bite. Robinson started experiencing pain in his knee the night of Aug. 24 and went to the training room at 7 the next morning to have it examined. He went back again, but "it wasn't bad enough to raise any eyebrows," Robinson said.

By the next night, though, the situation had changed.

Robinson was eating dinner with Sinz when the pain intensified.

"I'm going to text the doctor and tell them, 'Hey, it's getting really bad. I don't know what it is. Something needs to be done,' " Robinson recalled. "If he doesn't text me back in 10-20 minutes I'm going to the hospital because it hurt so bad.

"By that time, my whole leg was swollen and my knee was a mess. I didn't know if it's a bug bite or not but it's something. My leg blew up and I couldn't move my knee."

Robinson didn't practice all week. On Tuesday, he had ice on his knee through most of the practice. He was given antibiotics to treat the swelling and the medicine eventually worked.

When Robinson wasn't at practice or class, he was on the couch in his apartment.

"He patrolled the couch the whole week," Sinz said. "He had a big lift system, keeping it elevated. Sometimes, I would be there fighting for a couch spot. I obliged and let him take it over because I knew it would be big for him to get back."

Robinson played most of the opener, finishing with three tackles, as the Boilermakers outlasted the Broncos to snap a 10-game losing streak. During the game, Robinson said his knee was tight but the swelling was confined to just his knee instead of his leg.

He didn't practice Tuesday and is considered day-to-day but fully expects to play Saturday when Purdue hosts Central Michigan.

It turns out the infection stems from a cut he suffered during training camp which never healed.

"I don't want to call it a turf burn but it kept getting open and open in camp," he said. "Getting down to take a knee or getting on the turf, you know how much bacteria is on the turf. It gets down below in a secondary spot where an infection starts. That's what it's from."

Central Michigan at Purdue, noon Saturday, ESPN News