MILWAUKEE -- The Brewers are pressing the pause button on top pitching prospect Jacob Misiorowski’s sensational season.

The 21-year-old right-hander -- No. 38 on MLB Pipeline’s Top 100 prospects list and the No. 4 Brewers prospect -- developed arm fatigue in the wake of an Aug. 15 start for Double-A Biloxi in which Misiorowski allowed one hit in six scoreless innings and matched the franchise record with 12 strikeouts. On Saturday, the Shuckers formally placed him on their seven-day injured list.

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Initial tests did not prompt significant concern about structural damage, but out of caution, the Brewers have shut Misiorowski down for the time being. Brewers general manager Matt Arnold said the club believes the issue is just fatigue, brought on by Misiorowski's meteoric rise and career-high workload, which can be cured by a couple weeks of rest. In a sign of that confidence, Arnold was still not ready to totally rule out the chance of Misiorowski pitching as a Major League reliever late this season if circumstances call for it.

"I think it's less likely now," Arnold said, "but I don't want to close the door on that."

Overall, Misiorowski has a 3.41 ERA this season and has struck out 110 of the 314 batters he has faced in 20 starts from Single-A Carolina to High-A Wisconsin to Double-A Biloxi, where he appeared to settle into a groove after two rough starts following his latest promotion. Those outings came after he shined in the All-Star Futures Game, topping out at 102.4 mph during a scoreless, three-strikeout inning.

At 71 1/3 innings among the three affiliates, he was nearing his innings limit. So the timing of this pause is less consequential from the perspective of building him up for future seasons than if it had happened early in the year.