MILWAUKEE — The first-place Milwaukee Brewers finished a grueling stretch of 19 games in 18 days by dealing with one more potential loss to their injury-riddled bullpen.

Shelby Miller left because of an injury in the eighth inning of the Brewers’ 10-8 loss to the Philadelphia Phillies on Monday.

“He felt something pop in his elbow,” Brewers manager Pat Murphy said after the game, adding that the right-hander would undergo testing.

Miller had just thrown a pitch to Max Kepler when he reacted in discomfort before leaning forward and putting his hands on his knees. After Brewers officials went to the mound to check on him, Miller headed into the dugout as Rob Zastryzny came out of the bullpen with a 2-2 count on Kepler.

Miller, who has a 2.74 ERA in 48 appearances this season, was acquired from the Arizona Diamondbacks at the trade deadline. The Brewers activated Miller, 34, from the injured list Aug. 8 after he missed about a month because of a right forearm strain.

The Brewers own the best record in the majors and lead the Chicago Cubs by 5½ games in the National League Central after going 9-10 in this brutal 18-day stretch. But the health of Milwaukee’s bullpen is a major concern.

All-Star closer Trevor Megill went on the injured list last week because of a right flexor strain. Left-hander DL Hall (right oblique) and right-hander Grant Anderson (right ankle) also are on the injured list.

All those injuries have put a strain on Milwaukee’s remaining relievers, and that appeared to be the case Monday when the Brewers squandered early leads of 4-0 and 5-1. That matched the biggest lead Milwaukee has blown in a loss this season.

After Brewers starter Jacob Misiorowski allowed one run over 4⅓ innings, the Phillies scored three runs off Nick Mears in the sixth inning, two off Miller in the eighth and two off Abner Uribe in the ninth.

“You watch 162 games, your bullpen’s going to let you down sometimes,” Murphy said. “It’s just what happens. Is it because of the long stretch? I’m certain that doesn’t help.”

That bullpen will get a welcome break Tuesday when the Brewers have their first day off since Aug. 14. Then, they’re back at American Family Field on Wednesday to resume this series with the NL East-leading Phillies in a potential playoff preview.

“I’d be lying to you if I told you the past few days of this stretch has been easy,” Uribe said through an interpreter. “But at the same time, we have the off day tomorrow in which I think we’re going to be able to bounce back as a whole, and everybody will be ready to go.”

The frustrations of this long stretch boiled over in the ninth inning when the Phillies staged their winning rally with the help of a controversial call.

Uribe walked Kyle Schwarber to start the inning, then struck out Bryce Harper before reaching a 3-2 count on J.T. Realmuto. The next pitch was low and outside, and Realmuto started to offer at it before attempting to check his swing.

After Realmuto was awarded first base, Murphy argued that the batter had gone around and didn’t check his swing. Murphy was ejected from the game by first-base umpire Jim Wolf, then Brandon Marsh hit an RBI single to put Philadelphia ahead for good.

“Umpires have a hard job,” Murphy said. “They have a hard job. What I don’t like is when they’re definitive they got it right, and then I see what I see after the game, and you can see the barrel’s out in front of his front leg. Tell me how the barrel can be in front of his front leg at any moment, and it not be a swing.”