Oakland Athletics pitcher Sean Manaea has been diagnosed with a right rhomboid strain.
Manaea left Monday's start against the Houston Astros in the bottom of the fourth inning, and is being called day-to-day with what amounts to a sore back.
Manaea has had some struggles in his rookie campaign, and owns a 4.40 ERA and 4.12 SIERA through 21 games this year. He is also sporting a 20.6 percent strikeout rate, 6.3 percent walk rate and a 1.26 WHIP through 120 2/3 innings pitched.
Source: Rotoworld.com