Baker will start Thursday's game in St. Louis in what's expected to a bullpen day for the Orioles, Rich Dubroff of BaltimoreBaseball.com reports.
Baker hasn't recorded more than five outs in any of his 11 appearances out of the Baltimore bullpen this season, so he's unlikely to pitch more than two innings before checking out of the contest. The Orioles don't have an obvious primary pitcher to work behind Baker, but converted starter Keegan Akin could offer a decent amount of length while he's available in the bullpen on three days' rest.