Simonini played college football at Texas A&M under head coach Emory Bellard, and led the Aggies in tackles for three straight seasons.

In 1979, Colts head coach Ted Marchibroda informed Simonini that he'd lost his starter role to rookie Barry Krauss.

Krauss, a highly touted first-round draft pick, was overmatched, and Simonini quickly regained his starting job.

[5] In 1981, with the Colts dealing most of their key veteran players, and in a total rebuild mode with new head coach Frank Kush, Simonini requested his release and finished his career with the New Orleans Saints in 1982.

[4] The Saints traded Simonini to the Miami Dolphins ahead of the 1983 season but he opted to retire rather than relocate to play with the franchise.