Ballweg hails from Waverly, Iowa, he has 57 career wins and is ranked No. 8 at 149 pounds his senior season.
Chiri is a native of New London, Iowa. He saw action in five duals as a sophomore, but has been slowed by injuries over the last two seasons.
Gambrall, a native of Iowa City, Iowa, has 62 career wins and was an All-American in 2011, finishing third at 184 pounds at the NCAA tournament.
McDonough has won 115 career matches and owns the fourth-best winning percentage in program history. The Marion, Iowa, native is a two-time NCAA and Big Ten champion.