MILWAUKEE -- Brewers reliever Jeremy Jeffress landed unexpectedly on the 10-day injured list Sunday with a left hip injury that he said has been bothering him over the past week.

The Brewers called up fellow right-hander Ray Black to replace Jeffress, who reported discomfort the morning after a 2 1/3-innings outing against the Nationals on Aug. 17. He has pitched twice since then and felt discomfort after leaving the mound each time.

“It’s not something I feel as I’m pitching. It’s the next day; stiffness and kind of tight. It just hasn’t gotten better,” Jeffress said. “After I pitched twice, I feel like it hasn’t gotten better, so I told the trainers I wanted to nip it in the bud and get ready for the most important part of the season, which is the back half of September.”

Is he hopeful of a minimum 10-day stint?

“I can’t predict the future,” Jeffress said. “I know if I keep throwing on it and not treating it, it’s going to get worse. I feel like, ‘Give me the time I need and get it back right.’

“I’m getting old for sure. It’s just part of pitching, man. Part of being an athlete. Wear and tear is part of the season. All the intensity that I’m using in my body, using different muscles throughout the season because you tweak your mechanics and stuff like that.”

It has been a trying season for Jeffress, who a year ago was as valuable, if not moreso, than left-handed relief ace Josh Hader. Whether it was a toll from a career-high 73 appearances during the 2018 regular season plus eight more during Jeffress’ tumultuous postseason, or the impact of the tightly-wound baseballs which have affected a number of pitchers who use split-fingered fastballs, or simply the ups and downs associated with relief pitchers, he has not been the same pitcher in ‘19.

Jeffress’ struggles started in Spring Training with a shoulder issue that delayed his season debut until April 17, beginning a year in which he has logged a 5.02 ERA and a 1.37 WHIP, up from 1.29 and 0.99 in 2018. His eight strikeouts per nine innings are down from 10.4 last season.

“He set the bar really high last year,” Brewers manager Craig Counsell said. “He had an incredible season last year. Results wise, it was better than Josh's season, it really was. He had a wonderful year last year. With injuries and some inconsistencies, it just hasn't been the same.”

Still, with the Brewers employing a depth approach to the pennant race, Jeffress has the potential to deliver meaningful innings in the final weeks of September. Counsell agreed that the best course was to try to get him 100 percent healthy.

Black, acquired with Drew Pomeranz from the Giants at the Trade Deadline, already had one stint with the Brewers this month and made two appearances.

“The thought was the best way to get rid of it was 10 days off,” Counsell said. “[Jeffress] was unavailable last night, and we were going to try and give him a couple days off. But in the end, it was just better to get a pitcher here and give him 10 days off.”

Said Jeffress: “There’s things I’ve definitely been working on that I’ve improved. Like I said, if I nip this in the bud and make sure the back end of the season is there and I’m healthy, everything will be all right. … My other parts are great, I swear. I’m 32 next month!”