Change #5 - Call up Luken Baker and Oscar Mercardo, send down Alec Burleson and Tres Barrera
Alec Burleson is a valuable part of the Cardinals' future. Right now, he's hardly playing and doesn't have a clear role, so why not call up one of the hottest bats in all of Triple-A and see if you can catch lightning in a bottle in Luken Baker.
If you haven't been keeping up with the Memphis Redbirds, Baker is slashing .302/.430/.672 with 12 HR and 29 RBI in just 33 games thus far. Baker is 26 years old and has nothing left to prove in Triple-A, so why not let his bat go to work for the big league club?
The nice part about having Baker on the roster off the bench is if it works, you may have found the next Cardinals prospect to rise from being relatively unknown to a key member of the club. The Cardinals clearly don't value his future like some of their other young bats, so they don't have to worry about stunting his growth or development. Worst case, he was disappointing off the bench and goes back to Memphis soon.
Burleson can go down to Memphis and play every day, getting ready to be an important contributor for the club once again in the near future. He's now slashing .218/.269/.402 on the season and just doesn't have the same punch he had during the first few weeks. I expect him to regain that, but for now, a trip to Memphis makes sense.
Tres Barrea doesn't need to be on the roster if Contreras is catching, unless he's replacing Andrew Knizner. Oscar Mercado was signed as a depth outfield option this offseason, and could provide outfield defense off the bench late in games if the club needs to move Donovan into the infield, and also wouldn't require much playing time.