The team says the 6-foot, 240-pound Freeman signed his one-year offer Monday as the Colts began their second week of offseason workouts.
Ten games slated to air on WANE-TV including season opener against Bills on September 13.
Mutscheller played for the Colts from 1954-61 and made the Pro Bowl in 1957.
A shoulder injury forced the 26-year-old to miss all of last season.
Games against Eagles, Bears, Rams, and Bengals.
The team announced it would be keeping Luck thanks to a fifth-year option in his rookie contract.
The Indianapolis Colts have found another potential starting safety in free agency, agreeing to terms with Dwight Lowery
After running 78 times for 351 yards with one touchdown and catching 21 passes for 173 yards in the regular season, Herron ran 45 times for 170 yards and two TDs in three playoff games.
Brown, 5-11, 190 pounds, was originally selected by the San Diego Chargers in the third round (82nd overall) of the 2011 NFL Draft.
The Indianapolis Colts have signed undrafted free agent tackle Demarco Cox, a former basketball player at Ole Miss and Georgia Tech.
Richardson was acquired by the Colts in a trade with the Cleveland Browns on September 18, 2013.
On Tuesday, running back Frank Gore signed with Indianapolis and on Wednesday free agent wide receiver Andre Johnson decided to join his former college teammate.