The Blues get the 70th overall selection in the draft, which starts Friday and runs through Saturday. The Maple Leafs originally acquired the pick from the Florida Panthers in exchange for Chad Kilger on Feb. 26.
Mayers, a 6-foot-1, 214-pound Toronto native, has played parts of 10 NHL seasons, all with the Blues. He had 12 goals, 15 assists and 91 penalty minutes in 80 games with the St. Louis last season. Overall he has 51 goals, 58 assists and 576 penalty minutes in 435 games.
The Blues originally selected Mayers in the fourth round in the 1993 draft.