PEORIA, Ariz. — Mariners center fielder Franklin Gutierrez was scratched from an intrasquad game Tuesday and taken by a trainer for an MRI exam of his upper body after experiencing pain while throwing in a morning drill.

Gutierrez later returned to the Peoria Sports Complex, but was awaiting word on the test results. Mariners manager Eric Wedge said Gutierrez appeared to have suffered a pectoral muscle injury in his chest.

"We don't really know anything yet," Wedge said. "We're waiting on the MRI results and figuring out what the game plan's going to be after we get that back. He felt something in the pec region when we were taking infield today, so we'll wait and see what the results show and go from there."

Wedge said he watched Gutierrez hurt himself while making throws to third base from center field. Gutierrez endured a terrible 2011 season blamed largely on his late start due to an irritable bowel syndrome condition that began impacting him late in the 2010 campaign.

The team says those problems are now contained and Gutierrez arrived in camp with 15 added pounds of muscle.

Gutierrez showed off his strength in an intrasquad game Sunday, going 3 for 3, including a leadoff home run against Felix Hernandez.

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com. On Twitter @gbakermariners.

Read his daily blog at www.seattletimes.com/Mariners.