ST. LOUIS - The Cardinals on Monday optioned reliever Keith Butler to their Triple-A farm team in Memphis.

Butler, the former Wabash Valley College pitcher, appeared in 12 games. He allowed just three earned runs in 12.2 innings of work for an ERA of 1.98.

The announcement was made on the Cardinals Twitter account. No accompanying roster move was announced, leaving the club with one spot open at the All-Star break. With starter Joe Kelly apparently headed back to the bullpen, according to media reports, the Cards could use Butler’s spot for a starting pitcher or other position player once the club resumes the season on Friday.

Righthander Carlos Martinez was recently called up from Memphis, and the club is still finding a role for him on the staff. It may be long relief, according to media reports.

The possible return of veteran starter Chris Carpenter looms for the Redbirds as well. Carpenter, who has not pitched all year, will begin a rehab assignment at Class AA Springfield, Mo. on Monday. The Cardinals can keep him in rehab for up to 30 days, then must either activate him or place him back on the disabled list.

Butler, who began the season in Springfield, was called up on May 31, but had been used only twice since June 25.