The 6-2, 238-pound Sweat was injured during the team's Sept. 11 victory against Miami (Fla.) but did not leave the game.
"He probably should have, but everyone (act like they are) all right," Tressel said. "You know how that goes."
After missing most of last season and spring practice with a knee injury, Sweat returned to action this fall and overtook Etienne Sabino for the starting strongside linebacker position. In the first two games of the season, Sweat had recorded three tackles while playing exclusively in OSU's base defense and on special teams.
Tressel would not disclose the nature of the injury but said it is not related to his previous injury and said it should not have a long-term effect.
Stepping into Sweat's role is not Sabino, who figures to redshirt this season, but sophomore Jonathan Newsome. The 6-3, 219-pound linebacker saw action in five games as a freshman and recorded five tackles on special teams.
"He has done a nice job on the special teams thus far this year," Tressel said. "He'll have opportunities this weekend in the base defense. I don't know for sure how Ohio University is going to deploy, so I don't know for sure how much we'll be in base or nickel."
If the Buckeyes open in their base defense, Newsome will not be the only new starter. Sophomore strong safety Orhian Johnson will take over for C.J. Barnett, who suffered what is likely a season-ending knee surgery in the Miami victory.
Tressel said the 6-2, 205-pound Johnson brings a few different things to the table compared to the 6-0, 190-pound Barnett.
"Orhian is a different body type," Tressel said. "He has a lot more size. He might have a little more range. C.J., I thought, was really evolving as a very physical, active guy with excellent quickness. He didn't weigh a whole bunch. There were times when you were thinking, ‘Can you come down in that box and splatter people at (190) pounds for 12 weeks and stay alive?'
"They're a little different style, but as long as assignment-wise they're both in the right place they both can do it for you. They're both capable."
Tressel said he was pleased with Johnson coming out of spring football but was disappointed that he missed around a dozen practices due to a calf injury. In addition, the coach said fifth-year senior Aaron Gant and junior Nate Oliver are in the mix.
"We need (Johnson) to be good," Tressel said.
The two injuries might not come as a surprise given the physicality of the win against the Hurricanes. Tressel said he noticed that his players seemed more bruised this week than following a typical game and added that it took longer for them to get past that.
As the Buckeyes have worked to improve their special teams this week, Tressel said they will continue to use freshman Drew Basil as their primary man on kickoffs. Last week, he was replaced on the majority of kicks after he had one returned for a touchdown in the first quarter. Sophomore Ben Buchanan, who has experience as a punter and kicker but is serving in the former role this season, is not in the equation, Tressel said.
The trio learned of their honor Wednesday at a team meeting. Malone and Crawford are set to graduate this fall or winter and Sika is a graduate student so he will receive an entire year's worth of his master's degree paid for.
"Those guys have been here a long time and taken a lot of snaps in practice and not gotten a whole bunch of glory," Tressel said. "Ricky hasn't stopped smiling. I think he slept last night with a smile. Our guys know the difference between how fortunate they are on scholarship and those that are just fighting the fight and working part-time jobs and all the rest just to have a chance to be a part of it."
Crawford has changed positions from wide receiver to tight end and is now third on the depth chart at that position.
"He does an outstanding job," Tressel said. "I wouldn't be afraid to put him in anytime in the pass part of it. He hasn't had as much experience in point-of-attack blocking and adjustments in pass protections, but he's a good kid. He makes plays on scout team against our guys all the time."