Barclay, a walk-on junior who made his debut last week after Pettrey was injured, would be the kicker if there were a game today, but Buchanan, a redshirt freshman scholarship player, could earn the job if he has a strong week in practice after missing last week.
"I'm told by the trainers that he'll be able to work today," Tressel said while not identifying what kept Buchanan out of the lineup. "So between Devin and Ben, we've got to step up. I'm not sure any of us expected that, but that's part of football.
"If we had a game this moment, Devin would kick off and kick field goals because I haven't seen Ben for a week but we have Tuesday, Wednesday, Thursday practice."
Tressel did not rule out using both players.
Boren started at left guard the first eight games of the season and has generally been regarded as the team's best offensive linemen for the season. His return is welcomed as the Buckeyes get set to contend with stout Nittany Lion defensive tackles Jared Odrick and Ollie Ogbu.
Larimore was enjoying a fine season in the middle of the Ohio State defense before injuring a knee Oct. 3 at Indiana, and his return figures to be a boost for the Buckeyes as they face the Nittany Lions with tailback Evan Royster, the Big Ten's No. 2 rusher.
Then there is the status of Terrelle Pryor, the team's starting quarterback who sat out all of the second half of the last game.
"He has ice bags everywhere," Tressel said. "He's got one on his fingers and all the way down his body with his knees and his ankles and foot and so forth.
"We thought that he had been banged around enough, and even when you don't design things for him to get banged around, he likes to make plays and he attracts a crowd, but he'll be ready to go today."
The head coach supposed Herron was around 90 percent last week when he returned to action after missing two games.
"He didn't have quite that burst," Tressel said. "But now he's been out in a game and had a couple days rest, and November practices won't wear you out (because) they're not quite as long. Hopefully you don't get someone stepping on someone's foot and rolling an ankle or whatever, but, yeah, I feel like we're as good as we could be right now."