Walters lasted four innings in his Major League debut last weekend at Wrigley Field, enduring a rough first two frames before getting better in his last two. He struck out seven against two walks, but allowed a great deal of hard contact in the early going. In that same game, Boggs pitched two effective innings of relief.
However, the Cardinals believe that Boggs has too much difficulty getting warmed up quickly. They feel that Walters may be better suited to relief work, for the time being, for that reason.
"I think it makes more sense," manager Tony La Russa said. "Walters gets ready quicker. He's a better fit for the bullpen right now. Boggs takes more time, so he's a better fit for the rotation. Boggs is available as a reliever today. I think they both have shown well here."
Boggs began Spring Training ahead of Walters on the depth chart, and would have been the presumed first option if the Cardinals had needed a sixth starter in season. However, he missed time due to an injury early in the spring, while Walters pitched very well in camp.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.