MILWAUKEE -- Injuries continued to mount on Friday amid what amounts to a must-win stretch for the Brewers, who called up Minor League catcher Jacob Nottingham to protect against the absence of Manny Piña after Pina took a foul tip off the mask in Thursday’s loss to the Cubs.

Pina wound up exiting the game with what the Brewers termed “head discomfort.” Manager Craig Counsell said on Friday that Pina suffered a mild concussion.

“He came and saw the training staff today. We sent him home -- just an easier environment for him,” Counsell said. “He’ll come in every day and we’ll see how he’s doing. We’re going to be without him for a couple days, at least.”

Pina will have to pass a series of tests required by MLB’s concussion protocol before he returns to the field. The veteran plays a key role on days the Brewers face a left-hander, as they did in the first two games of their important four-game series against the Cubs when they faced Jose Quintana and Cole Hamels. Pina has a .969 OPS this season against southpaws, so he often starts those games behind the plate while switch-hitter Yasmani Grandal mans first base.

Nottingham logged five at-bats over parts of six games with the Brewers earlier this season and hit his first big league home run on May 17 at Atlanta. In the Minors, he slashed .231/.313/.355 with five home runs, representing a decline in a season in which offense was way up across the Triple-A level.

Nottingham thought his season was over. Teams always promote an extra catcher when rosters expand in September, and the Brewers went with Pacific Coast League batting champion David Freitas. But Freitas is more of a bat; should the Brewers need a catcher, Counsell said, Nottingham is more likely to get the call.

“I actually went home for a couple days and flew to New York yesterday. I was going to spend a week there and hang out, and then last night I got a call,” Nottingham said. “Quick turnaround, and I’m excited to be here. Obviously, this is where you want to be in your career. I’m very thankful for the opportunity to compete with these guys.”

Of his Triple-A season, Nottingham said, “It started off really good. Catching this year was really good -- probably the best I’ve been in my career. Hitting, I started off really good and then just ups and downs like a normal season. But I’m ready to go.”

The Brewers traded slugging outfielder Khris Davis to the A’s for Nottingham and pitcher Bubba Derby in February 2016. Nottingham had a reputation as an offensive-minded player then, but that is changing.

“I think when the trade occurred that was the question, probably, but as every year has gone on it’s probably flipped a little bit,” Counsell said. “He’s worked really hard and the defensive part, he’s become pretty darn good at it.”

Moustakas still sidelined

The Brewers hoped that an anti-inflammatory injection on Wednesday’s off-day would calm the discomfort in third baseman Mike Moustakas’ left hand and wrist. But so far, Counsell said, that has not happened.

“Yeah, not making great progress,” Counsell said Friday afternoon. “He was going to try to do a little bit more today but he was a little sore still when he came in. The swing, there’s still significant pain there. He’s going to try to increase activity, and then we’ll see how it goes.”

Counsell, Maddon to take part in first pitches

Here’s something Cubs fans and Brewers fans can unite to support.

Tom Schroeder, a Brewers supporter, underwent a heart transplant last August at Aurora St. Luke’s Medical Center that saved his life. Three months later he wrote a letter to the family of the donor, 32-year-old Joshua Holland, and received a letter back from Holland’s mother that included some information about her son and his life. Among the details included in Melanie Cook’s message was that her son had been a Cubs fan.

On Saturday at Miller Park, before the Cubs and Brewers meet for the next-to-last time in the regular season, both families will meet for the first time. Schroeder and the donor’s niece, Jerzie Wilkerson, will throw out ceremonial first pitches to Counsell and Cubs manager Joe Maddon.

“We all embrace the great rivalry between the Brewers and Cubs, but this is a story that goes well beyond what happens between the baselines,” Counsell said. “It’s another example of how baseball can bring together fans and families in unexpected ways.”