In 2000 the year Watson joined the Bills, the only other player to return punts was Peerless Price.
While he was a member of the Bills for the following two seasons, he entirely gave up punt return duties to the likes of Price, Nate Clements, and Charlie Rogers.
http://www.pro-football-reference.com/players/W/WatsCh20.htm
In 1999 the year before Watson arrived, Kevin Williams returned all but one punt with Peerless Price returning the other one.