ST. LOUIS -- The St. Louis Cardinals traded struggling reliever Mitchell Boggs to Colorado on Tuesday for the Rockies' international signing bonus slot No. 4.
In other news, St. Louis released veteran infielder Ty Wigginton and selected the contract of catcher Rob Johnson from Triple-A Memphis. All-Star catcher Yadier Molina returned to the starting lineup against Houston after missing two games with a sore right knee.
Boggs was 0-3 with an 11.05 ERA and two saves in 18 games for the Cardinals earlier this season. He was demoted to Memphis, where he went 0-2 with a 5.70 ERA in 18 games.
"He was disappointed," general manager John Mozeliak said. "He had high expectations coming into the season."
Boggs went 13-15 with a 4.15 ERA in 232 games for St. Louis from 2008-13. The 29-year-old right-hander was a valuable member of the Cardinals' 2011 World Series championship team and went 4-1 with a 2.21 ERA in 78 relief appearances last year.
Molina had an MRI on Sunday that showed no structural damage. He entered Tuesday night's game batting an NL-best .346 with six homers and 45 RBIs. He received the most votes among NL players in fan balloting and is set to make his fifth All-Star appearance next Tuesday at Citi Field in New York.
Molina had started 78 of the team's 87 games this season.
The 35-year-old Wigginton hit .158 with three RBIs in 57 at-bats for St. Louis.
Johnson, 30, was hitting .236 with seven home runs and 32 RBIs in 59 games at Memphis. He was in uniform Tuesday night against the Astros.