 With Montreal already having excellent goaltending from Patrick Roy and Brian Hayward, Riendeau was traded to St. Louis on 9 August 1988 with Sergio Momesso for Jocelyn Lemieux, Darrell May and St. Louis's 2nd choice (which became Patrice Brisebois) in The 1989 NHL Entry Draft.Riendeau was excited for his debut with St. Louis during the 1988–89 season.His first game was set to be on the road in Hartford.