DePiero became the head coach of the Generals late in the 2007–08 season, as Brad Selwood stepped down from the position. DePiero, who was an assistant coach, was promoted to become the head coach, and guided Oshawa to a 5–4–7 record in their last 16 games, as the team finished in second place in the East Division, and qualified for post-season play. The Generals then made it to the Eastern Conference finals before they were eliminated by the Belleville Bulls.
The Generals struggled in DePiero's first full season behind the bench, as the club began to rebuild, which included trading leading scorer John Tavares, Michael Del Zotto and Daryl Borden to the London Knights for a package of three players and six draft picks. Oshawa finished the season in ninth place in the Eastern Conference, failing to qualify for the playoffs.
In 2009-10, the Generals once again struggled, finishing with a 24-39-3-2 record, and missed the playoffs for the second consecutive season.
He has recently been relieved of his duties as head coach and GM of the Oshawa Generals and is now coaching Varsity hockey at St. Michael's College in Toronto. 
|Team||Year||Regular Season||Post Season|
|OSH||2007–08||16||5||4||–||7||(89)||2nd in East||Lost in Third Round|
|OSH||2008–09||68||25||35||–||8||58||9th in East||Missed Playoffs|
|OSH||2009–10||68||24||39||–||5||53||9th in East||Missed Playoffs|