Both expected new starters - end Nathan Williams and tackle John Simon - have played productive minutes previously in their careers, so confidence runs high that both will make seamless transitions to starting roles.
Four players does not an Ohio State defensive line make, however.
Heacock has long been fond of playing eight or nine linemen regularly, and five players are gone from the 2009 group that was the deepest seen in these parts in quite some time.
In junior end Solomon Thomas and sophomore tackle Garrett Goebel, Heacock has a pair of players who have taken redshirt seasons and turned heads during multiple springs while biding their time behind talented older players.
If their presence and continued maturation gets Ohio State halfway to a reliable second unit, the two players with the most pressure on them to perform become redshirt freshmen Melvin Fellows and Adam Bellamy.
"This camp is critical for them," Heacock said of Fellows and Bellamy. "They've got to make a lot of strides. They've got to get to a point where you can put them in the game and expect them to execute and be efficient and do things right.
"I think they had good springs, but we've got a ways to go before we've got the eight or nine guys we need to get a good rotation going. You're going to get into games with a lot going on and a lot of activity. They'll throw bubble screens and passes and you're going to have to be able to substitute."
Many fans are particularly anxious to get a look at Fellows, a five-star recruit from Garfield Heights, Ohio, who saw any chance to contribute as a true freshman last season wiped out by a knee problem.
He has All-Big Ten performer and All-America candidate Heyward in his corner this year as he tries to break through and earn playing time.
"Last year was very humbling for him being out a year, but this year I've constantly tried to stay on him, trying to keep him up, trying to mature him," Heyward said. "He's going to be a great player here. I can already sense that. He can definitely disrupt the flow of a game and I'm looking forward to seeing what he can do on the field. He's definitely gotten a lot stronger. We used to play around about his skinny legs, but he's definitely put in all the work he needs to do and I'm looking forward to what he can do this year.
"Melvin and Adam have been here for a year and we're expecting a lot out of them. That means stepping up to the plate every single day. Sometimes I'll be on them, but sometimes I'll encourage them. We're expecting a lot, and from what I've seen so far they're going to take some major leaps this year."