Quarterback Christian Hackenberg is healthy and will play Saturday against Illinois, Penn State coach Bill O'Brien said.

During his weekly press conference Tuesday, O'Brien said that Hackenberg practiced Monday and has shown no serious side effects from a hit he took in the first quarter against Ohio State. Hackenberg left the game in the third quarter and had his right shoulder wrapped on the sideline.

After the game, O'Brien said that Hackenberg played through some pain and wanted to continue, but the coach decided to insert backup Tyler Ferguson. On Tuesday, O'Brien said that Hackenberg "practiced really well" Monday and won't need any extra protective gear to play against Illinois.

Other notes from O'Brien's appearances at his Tuesday media sessions.

---At Monday's team meeting, O'Brien told his team that it went through "the highest of the highs and the lowest of the lows" in games against Michigan and Ohio State. He reminded players of the team's foundations (teamwork, toughness, practicing competitively, going to class), then presided over a "good practice."

"Losing sucks, don't get me wrong," O'Brien said. "But at the end of the day, if you've got a bunch of guys who show up like they did Monday, that's a pretty neat thing."

---O'Brien passionately defended first-year defensive coordinator John Butler, calling criticism of him "crap."

"John Butler is a hell of a football coach," O'Brien said. "I don't care what the scoreboard says or the yardage says, he's our defensive coordinator, he's my defensive coordinator, and I'm proud to coach with him. ... If anybody should take heat, it's Bill O'Brien, not John Butler."

---That being said, O'Brien was critical of his defense, which gave up 63 points and 686 total yards. O'Brien said the coaching staff may have to "simplify things" to prevent the coverage mistakes that happened against Ohio State.

O'Brien praised defensive tackle DaQuan Jones (who played with a shoulder problem) and linebacker Glenn Carson (who sustained a finger injury), but said that the team was "a little soft" in pass coverage.

"We need to be more aggressive in coverage," O'Brien said. "We can't be afraid to make a mistake. Take your shot."

---Safety Adrian Amos shifted back to cornerback last week and likely will remain there. O'Brien said that Amos and Jordan Lucas are the team's best options at cornerback.

---Running back Bill Belton, who gained 98 yards against Ohio State, has supplanted Zach Zwinak as the starter. O'Brien said he and Zwinak discussed the back's fumbling issues Monday. Zwinak has lost three fumbles this season, two in the past two games.

"I do think it's a little bit mental," O'Brien said. "These are unbelievable kids who are hard on themselves, and I don't think he should be that hard on himself."