After his appearance, Middlebrooks said the lower back strain that landed him on the disabled list last month felt better than he expected.
"Felt great," he said. "I really expected to come here and feel some tightness. I don't feel any, so that's a good sign."
Defensively, Middlebrooks did not field any ground balls but caught a pop fly to end the top of the first inning.
"It was kind of tough to see early in the game. I remember that from being here," Middlebrooks said. "The first three innings were kind of tough, (but) I felt like my timing out there was good."
Middlebrooks said he will play seven innings in Wednesday's game and nine innings on Thursday. He is set to return from the DL on Saturday. The third baseman said it's unclear at this point if he will play Friday night in Pawtucket or use the day to rest for his return to the majors.
"Just ready to ramp it up some more and see how it goes," he said.
The 24-year-old will meet with Red Sox medical staff in Boston on Wednesday morning, but said his rehab was mostly a matter of waiting for his back to loosen up.
"It was knotted up pretty bad. It spasmed up pretty bad," he said. "So we're just getting in there and trying to loosen it up. There were some massages, a lot of core work to strengthen my core. That was about it. It was more just a time thing."
Prior to his injury, Middlebrooks felt like he was beginning to pull out of an early-season slump.
"My last 10 games, I was really starting to stick my approach and starting to hit the ball hard," he said. "I was hitting balls right at people. But I was sticking to my plan at the plate and having good at-bats. Unfortunately I got hurt then because I was feeling like I was turning things around."
In Middlebrooks' absence, infielder Jose Iglesias has blossomed in Boston, making a strong case to stay in the majors even upon Middlebrooks' return, though as a utility infielder.
"He's a good player. We've known that for years. It's just the case of polishing him as a player," Middlebrooks said of Iglesias. "He can play anywhere in the infield. He's one of the best defensive guys I've been around."
In 10 games since being recalled to Boston, Iglesias has batted 14-for-33 with four RBIs and one home run.
"He's really swinging the bat well, with the homer off (Yankees pitcher Hiroki) Kuroda (on Sunday). We were pretty happy for him," Middlebrooks said. "He's a good guy, he plays hard, he plays the game the right way, so I'm happy for him."