upon graduation from boston college, o'shea became a graduate assistant at rhode island for the 1984-85 season before returning to the heights as a grad assistant at bc from 1985-86. after a two-year stint as an assistant at yale, o'shea returned to uri, joining al skinner's staff, where he stayed for nine seasons. while on the rams staff, o'shea was a part of two ncaa tournament bids along with two nit bids. he is credited with recruiting cuttino mobley among others to uri. o'shea followed skinner and returned to his alma mater once again after skinner accepted the boston college job in 1997. he remained on the staff until 2001, when he landed his first head coaching gig at ohio, just a year after the eagles won both the big east regular season and tournament titles, finishing with a 27–5 record and earning three-seed in the ncaa tournament.