Mets assistant general manager John Ricco said the club expects to have more information and a full diagnosis Tuesday. Until then, the team will not make a decision on any potential roster moves.
"With Shaun, we don't know what's going on, so we're going to get somebody just in case," Ricco said.
According to the Mets' official Twitter account, that somebody is right-hander Gonzalez Germen, who was headed to San Francisco on Monday. Germen is 3-3 with a 5.52 ERA in 35 relief appearances with Triple-A Las Vegas.
"Dr. Thompson is one of the top guys in the country," Ricco said. "We were in Milwaukee, so it was close. It is close to Shaun's home, so it was something he was comfortable with, so we decided to go that route."
Andrew Owens is an associate reporter for MLB.com. Follow him on Twitter @OwensAndrew. This story was not subject to the approval of Major League Baseball or its clubs.