"There won't be a guy there at this point," Counsell said before Friday's 4-3 win over the Cardinals. "We'll split time there. We'll just kind of see how it goes. I don't have a plan or anything specific laid out, but each guy hits right-handed. You hope a guy gets hot and take charge."
An infielder by trade, Perez forced himself into the lineup in the corner outfield spots by hitting .325 in his first 83 at-bats. Perez has been in a slump, hitting .170 over his past 18 games to lower his season batting average to .269 entering Friday.
Middlebrooks, who hit 17 home runs with Boston in 2013, had his contract purchased from Triple-A Colorado Springs on July 4. He started at third base Tuesday in Washington, while Perez got the call Friday against St. Louis.
The 27-year-old Middlebrooks was hitting .287 with 10 home runs and 47 RBIs for the Sky Sox.
Utilityman Jake Elmore and Yadiel Rivera, whom the Brewers recalled from Triple-A on Friday, can also provide coverage at third base.
"Now we have a group of bench players that are all multi-positional," Counsell said. "We just created another option there with Yadiel. Yadiel can be used in a late running situation or late defensive situation."
The Brewers traded Hill to the Red Sox on Thursday for Minor League pitcher Aaron Wilkerson and infield prospect Wendell Rijo.
Hill started slowly, but hit .323 after May 1 to raise his batting average to .283 to go along with eight home runs and 29 RBIs entering Friday. The veteran not only provided the Brewers with strong play on the field, but he also had a tremendous impact in the young Milwaukee clubhouse.
"Aaron was playing at a really high level," Counsell said. "He got off to a little bit of a slow start, but we stuck with him and he rewarded us for that. He has played really well over the last two months. His defense at third base has been plus defense on my end.
"You will hear it from everybody you talk to in the clubhouse that he was an important part. He was a vocal part of the clubhouse."
• Counsell announced that Matt Garza, Jimmy Nelson and Zach Davies will start for the Brewers coming out of the All-Star break.
• Milwaukee opens the second half with a three-game series in Cincinnati before heading to Pittsburgh for a three-game set.