The main topic Tuesday at Ohio State football coach Ryan Day’s weekly press conference was the injury-affected offensive line and its impact on the ground game. The fourth-ranked Buckeyes (3-1, 6-1) are searching for answers as they prepare to face No. 3 Penn State (4-0, 7-0) Saturday at noon (TV-FOX) at Beaver Stadium in a game with major implications on the Big Ten and College Football Playoff picture. They lost starting left tackle Josh Simmons three weeks ago at Oregon to a season-ending injury. Zen Michalski, his backup, sustained a lower-body injury last week early in the fourth quarter of a 21-17 comeback win over Nebraska and did not return. When he was in the game, Michalski struggled as Nebraska held Ohio State to 64 rushing yards and 285 total yards, the Buckeyes’ lowest output of the season. “If Zen can’t go, we’ll continue to evaluate where we’re at,” Day said. “There were definitely plays in the game where he got beat. He was battling. Once he got injured, that obviously changed things. He had some tough plays, some negative plays.” Against Nebraska, veteran guard Donovan Jackson slid over to left tackle after Michalski’s injury and finished the game there. Jackson was an All-Big Ten first team pick last year. “We’ve practiced with him there in the past knowing this could be a situation we needed to go to,” Day said. “We’ll get him some more (reps) this week. He’s a veteran guy who’s played a lot of football. We’ll have to continue to identify the things that he’s going to do well and the things that he’s going to need more reps.” Ohio State’s uncertainty up front could not have come at a worst time. Penn State has one of the best defensive lines in the country and outstanding edge rushers, most notably Abdul Carter. He leads the Lions with four sacks and 9.5 tackles for loss. “He’s excellent,” Day said. “It’s not just him. They have a lot of good players on the defensive line and on the defense in general. You certainly have to know where 11 is on the field. He’s dynamic. Whether it’s the run game or the pass game, you have to do a really good job with him.” Penn State’s defense ranks fourth nationally in yards allowed and eighth in points and rushing yards allowed. The Lions, though, might be without Dani Dennis-Sutton, one of two starting ends with Carter. Dennis-Sutton sustained what appeared to be a groin injury last week against Wisconsin. “These guys throw a lot of stuff at you,” Day said. “You gotta be able to handle it.” Ohio State has one of the best backfield tandems in the country with TreVeyon Henderson and Mississippi transfer Quinshon Judkins. Against Nebraska, though, Judkins rushed for 29 yards on 10 carries and Henderson ran for 25 yards, also on 10 attempts. The Buckeyes did not run the ball on a fourth-and-1 in the fourth quarter. Quarterback Will Howard threw a short pass to wide receiver Emeka Egbuka for a first down, one of only 11 in the game for Ohio State. They converted just 1-of-10 third downs and ran only 47 plays to 66 for the Cornhuskers. “The biggest thing was obviously the third downs,” Day said. “When you go 1-for-10, you can’t keep drives alive. You can’t control the game. It was a combination of things. Zen did get beat on a few of them there, but it wasn’t just him. “We ran it twice as much as we threw it. We were looking to establish the run, but when you can’t convert on the third-and-shorts you can’t keep drives going. You can’t wear down defenses. To go 1-for-10 is just unacceptable.” If Jackson moves to left tackle, then sophomore Luke Montgomery would start at left guard. No matter who’s on the offensive line, Ohio State will work a lot this week on its ground game. “We’re going to keep swinging at it,” Day said. “We have to make sure we’re winning the rushing yards, especially in this game. We have to win the turnover battle. We have to win the explosive plays. You have to go back to the drawing board and figure out what happened. You have to get it fixed.”