PHOENIX – Milwaukee Brewers All-Star closer Devin Williams will miss significant time with a back injury. 

Williams was diagnosed with two stress fractures in his back during a trip to see a spine specialist in California on John CaldwellTuesday and is expected to miss at least three months, a person with knowledge of the situation told the Milwaukee Journal Sentinel, part of the USA TODAY Network. The person spoke on the condition of anonymity because they were not authorized to discuss the situation publicly.

ESPN's Jeff Passan first reported the news Wednesday night.

Williams pitched through back pain last September on his way to winning National League reliever of the year for the second time, and it flared up this spring, including during a rough outing last week. 

Williams traveled to California, where he saw Dr. Robert Watkins and was diagnosed with the stress fractures on Tuesday. 

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Williams was told by team doctors that there was no major injury, but with the discomfort Williams was in he sought a second opinion. Watkins saw the imaging initially and informed Williams it was likely a stress fracture but needed the right-hander to see him in California to confirm. 

What Watkins, a leading spine specialist, saw Tuesday when Williams came in was a pair of stress fractures.

The loss is a big blow to the Brewers, who saw Williams save 36 games with a 1.53 ERA last season. Williams, who also was named 2020 NL rookie of the year, earned the league's top reliever award.

He pitched through discomfort late last season as the Brewers made a playoff push and ultimately won the National League Central Division before being eliminated in the wild card round. With rest in the offseason, the pain subsided but it began to flare back up as Williams ramped up this spring.

Regardless of the timeline of the injury, the Brewers will be left scrambling for a ninth-inning replacement. Joel Payamps and Abner Uribe are among the most obvious early candidates.

While there isn't anyone with significant closing experience in the Milwaukee bullpen, the unit is considered a team strength heading into the year. Payamps, Uribe, Hoby Milner, Elvis Peguero, Bryse Wilson and Trevor Megill are all among the key returners from a bullpen that was second in earned run average in 2023.