Stephen Drew got the nod at shortstop, which left Iglesias on the bench.
However, manager John Farrell made it clear that Iglesias, who thrived during the injuries of Drew and Middlebrooks this season, will play a semi-regular role.
"We're going to do everything we can to get [Iglesias] three days a week on the left side of the infield," said Farrell, "and everyone is aware of that plan going forward. The fact is, we have a pretty deep 25-man roster that we can afford to keep some guy's legs fresh as we get into the hotter months."
Pedro Ciriaco was the odd man out and was designated for assignment. The Red Sox could no longer justify keeping Iglesias at Triple-A.
"I don't know if it's forcing a hand," said Farrell. "I think players just tell you what they're ready for and how productive they can be and to what level they can contribute. In this case, we don't see Jose as strictly a utility guy.
"He's got a bright future ahead of him, but with the situation we're in right now, he's going to find himself at third or find himself at short or possibly at second on a given day. To have that type of performance and that type of confidence available to us, it makes us better."
Iglesias is hitting .446 in 74 at-bats while playing stellar defense at short and third.
"Good to be here and continue to help this team win some ballgames," Iglesias said. "I'll help in any way -- running, hitting, fielding."
Considering how well Iglesias has performed, it was a little different for Farrell to have to explain his role will be reduced at least somewhat.
"We recognize that he came up here when Will got hurt and he stepped in and did an excellent job for us," Farrell said. "Will's healthy, he's back, he's in the lineup. Jose knows that he's got a bright future here and he's earned his way to remain on this roster rather than go back down to Triple-A. I'd rather view it as all positives rather than delivering maybe a difficult message to Jose."
Middlebrooks, who is no small part of the Red Sox when he's swinging the bat well, was happy to return from his back injury.
The Red Sox wanted Middlebrooks to use his Minor League rehab assignment at Triple-A Pawtucket not just to get healthy, but to regain his consistency at the plate.
"I'm an aggressive hitter, as we know. I kind of quieted down a little bit, getting myself to good counts and knowing when guys are going to throw me those borderline pitches, and either take them for a strike or let them break off the plate," Middlebrooks said. "I'm just working on my approach. That's really the main thing: having good focus and being consistent with that throughout a game and not just for a couple at-bats. Just trying to stay focused. I think I did that. I felt really good about it."
Drew had been getting quite a few days off against left-handed pitchers anyway, so his playing time might not be that different. But Middlebrooks and Iglesias will both try to become accustomed to the rotation system.
"This isn't going to be strictly a matchup thing," Farrell said. "There may be a left-handed matchup when [Drew] plays shortstop on a given day or if there's a lefty on a day game following a night game and we can give Stephen a day down. That would be part of it. Stephen has done a very good job for us at shortstop, defensively. He's been streaky at the plate. We feel good about our infield depth."