After graduating from Gannon University,[1] Grilli was signed as an undrafted amateur free agent by the Tigers in the middle of the 1970 season, although he didn't make his major league debut until five years later at the age of twenty-six on September 19, 1975 as a reliever in a game against the Boston Red Sox at Tiger Stadium in which he pitched three innings and allowed one hit without surrendering a run.

[2] Plagued by control problems with his pitches and walking more batters than he struck out,[3][4] he worked out of the bullpen for the next two years until being purchased by the Blue Jays before the 1978 season.

[5] Grilli made his final major league appearance on September 17, 1979 in a loss against the Boston Red Sox at Exhibition Stadium in Toronto.

[6] He was traded to the Orioles organization during the 1981 season, and played for their AAA affiliate, the Rochester Red Wings.

[5][9] Grilli also is the owner of a bar in the city of Syracuse, New York, called "Change of Pace”.