I normally just link these stories, but here's a copy and paste from SeattleMariners.com:
"Seattle Mariners Executive Vice President & General Manager of Baseball Operations Bill Bavasi announced today that the club has placed outfielder Chris Snelling on the Major League 15-day disabled list with an impingement in his left shoulder.
Snelling was recalled from Tacoma July 26.
'Our plan was to option Chris back to Tacoma today,' Bavasi said. 'However, he's been on the medical report in Tacoma and when our trainers examined him here prior to yesterday's game, they recommended he not play outfield for several days. We determined that the proper and fair thing to do would be to place him on the disabled list until he is fully healthy prior to optioning him back off the roster.'
Snelling, 23, hit .247 (45x182) with 30 runs, 12 doubles, 4 home runs, 4 stolen bases and 34 RBI in 52 games with Tacoma this season. He hit .322 (19x59) with runners in scoring position and .313 (5x16) with runners on base and two outs. Snelling began the season on the disabled list recovering from ACL surgery on his left knee. He joined Tacoma on injury rehab May 10 and was activated from disabled list, and optioned to Tacoma, on May 20.
Snelling played for the Mariners in 2002 and 2005 with a combined .214 average (12x56) in 23 Major League games."