As an 18-year old, he spent a year playing junior hockey with the Des Moines Buccaneers and finished second in team scoring.
Riddle was named team captain for his senior season and continued to lead the Gophers on offense.
He led Minnesota to its second-consecutive conference championship and fourth-consecutive NCAA tournament appearance while finishing second in team scoring once more.
After graduating with a degree in communications, Riddle signed with the Blues and joined their AHL affiliate the Worcester IceCats.
A year later, Riddle signed on with the Tohoku Free Blades and though he played well, finishing second in scoring, the team did not and missed the postseason.