Boston was selected eighth overall by the Arizona Cardinals in the 1999 NFL Draft. The 29-year old played 56 games with the Cardinals and teamed up with QB Jake Plummer to lead the NFL in receiving yards with 1,598 in 2001, the same season he was named to the NFL Pro Bowl team. His receiving yards total still stand as the highest single-season total in club history, and at the time (23 years, 4 months), he became the second-youngest player in NFL history to reach1,500+ receiving yards in a season.
Well being in a pass happy league will be an advantage. I mean comparing other ex-NFL Pro Bowlers that Toronto signed in recent memory bringing in a receiver makes more sense than a running back in this league.