Gutierrez was scratched from the afternoon's intrasquad game and underwent an MRI test later in the day after being taken off the field in the morning workout after injuring himself while making throws in the outfield.
Gutierrez played just 92 games last year due to digestive issues that wiped out the start of his season and then a strained oblique muscle that landed him back on the disabled list in the final month. He reported to camp two weeks ago having put back on about 20 pounds of muscle after learning how to deal with Irritable bowel syndrome, but now will have to see what happened to his right chest area on Tuesday.
"We don't really know anything yet," manager Eric Wedge said. "We're waiting on the MRI results and will figure out the game plan after we get that. 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 saw Gutierrez grimace when making a throw, then shut him down after he continued struggling on his next effort.
"He'd thrown the ball a few times before that and he played catch well," Wedge said. "He's been great all camp. As you all know, he looks great. So it's just one of those things and we'll see."
Gutierrez hit just .224 last year with a .273 slugging percentage after the stomach issue eliminated much of his offseason conditioning and resulted in him dropping to as low as 175 pounds on his 6-foot-2 frame.
But he reported to camp at 200 pounds and said he felt the best he's been since 2009, when he hit .283 with 18 home runs, 70 RBIs and a .425 slugging percentage in his first season in Seattle.
Former Giants outfielder Darren Ford replaced Gutierrez in the intrasquad game as a non-roster invitee on a Minor League contract. Michael Saunders played center field for the opposing team and went 2-for-4 with one triple, one home run and two RBIs. Other center-field candidates in camp include Casper Wells and Trayvon Robinson.