The Marlins made the move before the start of a six-game trip Friday in Colorado. The injury forced Sanchez from Thursday's game against Atlanta in the fifth inning. He had given up to home runs before his exit, which extended the Marlins dubious streak of 20 consecutive games without a starter winning a game.
Top infield prospect Chris Coghlan was recalled from Triple-A New Orleans, where he hit .344 in 25 games. Coghlan will be available to spell second baseman Dan Uggla and third baseman Emilio Bonifacio, both struggling for the slumping Marlins.
Sanchez had shoulder surgery in June 2007 and returned last July. As a rookie in 2006 he went 10-3 and threw a no-hitter against Arizona, but he's 1-4 this year with an ERA of 5.79.
The Marlins initially said Sanchez's injury was a strained shoulder, then said a sprain was the proper term.