The Athletics have shut down top pitching prospect A.J. Puk with biceps soreness, according to a report from Susan Slusser of the San Francisco Chronicle. At this point, the severity of the injury is not fully known, though indications are that the exciting young lefty will be able to return to the hill before too long.

Needless to say, any issues in that region of such a valuable arm are going to be dealt with quite cautiously. Per the report, Puk has already undergone an MRI that did not give cause for concern that there is “any major structural damage.” Still, biceps soreness is a symptom associated with potentially serious elbow issues and the club will want to be certain that the current problem is not exacerbated.

Puk was taken with the sixth overall selection in the 2016 draft and turned in a solid, 125-inning effort in 2017. Splitting his time between High-A and Double-A in his first full season as a professional, the 22-year-old ran up a 4.03 ERA with 13.2 K/9 and 3.5 BB/9.

Oakland had already determined that the high-powered southpaw would not crack the roster out of camp. But A’s fans were already no doubt looking forward to his arrival sooner than later after watching him spin over nine scoreless Cactus League innings this spring before he was finally touched in his last frame. There’s no particular reason to believe that Puk’s ultimate ascension will be slowed significantly, though perhaps now the Oakland organization will handle him with added care early in the 2018 season.