He played college football for the San Diego State Aztecs, Vanderbilt Commodores, Northwest Mississippi Rangers and South Carolina Gamecocks.
He saw limited action in college but nonetheless was able to sign with the NFL's St. Louis Cardinals and made the team in 1986.
[3] Monaco began his collegiate career with the San Diego State Aztecs in 1981, lettering while being a backup inside linebacker that year.
[8] Monaco went unselected in the 1986 NFL draft and afterwards signed with the St. Louis Cardinals as an undrafted free agent, joining his brother Rob.
[11] When the NFLPA went on strike mid-season in 1987, Monaco was signed as a replacement player by the Green Bay Packers and was named starter.