Jones has already played a major role as he broke into the starting lineup last season and is set to start at the STAR spot this fall.
Entering their sophomore seasons, Harris and Davis are set to get on the field and contribute.
"Darien Harris is going to play a little bit of the STAR position and a little bit of the MIKE," defensive coordinator Pat Narduzzi said. "He has played both, I don't know if he's a backup there or not. I think it's him and (Kyler) Elsworth, really.
"We feel comfortable with both and he's had a lot of reps there. He's shown some very good promise at that position. We hate to backup a senior with a senior, so that's why we've gotten him a lot of reps."
Davis, who has been praised throughout camp, is healthy and ready to contribute.
"Ed's a football player and he's got great instincts," Narduzzi said. "He makes plays, so yeah, we see him getting a good amount of time. He's just tough and he's physical and he's got great instincts for the football."
Davis has five career tackles. Harris has four career tackles, all on specials teams.
Narduzzi stressed that finding a rotation of player to keep others fresh is a focus early this season.
"It's real important," he said. "We just had a how are we going to play the players meeting and it's real important. We've got to get some guys out there without giving up much. I think we've got some guys that just need some confidence that they've done it, they've been out there before we get into the Big Ten schedule."
Head coach Mark Dantonio said Tuesday that he feels like Michigan State has seven linebackers that are "game ready to play." He mentioned specifically Davis having a great camp and also that Harris had a great showing in one scrimmage.