Villanueva surrendered seven runs over just 2 1/3 innings during Friday night's 12-1 loss to the Rays. After the game, Villanueva admitted he didn't get anything behind the ball as evidenced by a decrease in velocity and flat action to his secondary pitches.
"He feels a little bit more soreness from his previous starts, which is not to be totally unexpected at this time of the year," manager John Farrell said. "If need be, if that soreness persists, we'll take every measure to identify if there's anything going on there physically. But it wouldn't be totally uncommon to feel a little bit more soreness."
Most pitchers are forced to go through periods of fatigue at this time of the year. The only thing that makes Villanueva's situation stand out is that he went through a similar experience in 2011.
Villanueva was forced to the 15-day disabled list after 13 starts with fatigue and a right forearm injury. So far this season, he has made 15 starts, so it's understandable there will be a close eye on the veteran right-hander for the rest of the year.
Friday's outing, though, was the first time Farrell saw any indications of Villanueva being flat on the mound. One start won't cause anyone in the organization to panic, but it's a scenario that still will be closely monitored.
"He was a little flat," Farrell said. "Their hitters indicated that as well. It's not because of a lack of effort, preparation. Physically, he wasn't as he has been of late.
"Particularly the late action to both his changeup and his slider. Those are the things that really shine through. Velocity can be somewhat comparable, but it's the late life to the secondary pitches that indicate he might not feel as sharp."