The San Francisco Giants are fighting for their spot atop the fiercely competitive National League West division.

The team embarked on a significant overhaul after posting a losing record last year, bringing in franchise icon Buster Posey as the new president of baseball operations. And among the immediate changes he made to the roster was a deal to bring in three-time Cy Young Award winner Justin Verlander.

The 42-year-old has made 10 starts for the Giants this year, posting a decent 4.33 ERA across 52 innings. After years of injury setbacks, it seemed Verlander had figured out a way to remain healthy and effective in his 20th big-league season, at least until the team got some bad news following his latest start.

“Verlander won’t detail what he was dealing with but he wasn’t totally right physically,” the San Francisco Chronicle’s Susan Slusser reported, shortly after Verlander lasted just four innings against the Athletics. “He said the coaches and trainers knew it was nothing that would create more problems. His velocity was down 3 mph.”

Following the game, manager Bob Melvin directed questions about the injury to Verlander, who would not provide more detail on which part of his body felt injured. And while the pitcher said he was “optimistic” that he’d be making his next scheduled start, there is reason for concern.

“Verlander was limited to 17 starts last year in Houston because of right shoulder inflammation and neck discomfort, but there have been no hiccups in his first season in San Francisco, at least until Sunday,” Alex Pavlovic wrote for NBC Sports. “The oldest player in the big leagues has thrown well in recent weeks, but on Sunday it was about limiting damage.”

After logging nearly 3,500 innings in his career, any setback for Verlander seems like a real reason for concern in San Francisco. There is still some mystery surrounding this latest injury but the Giants might need to start planning for a missed start.

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