Four days after outfielder Brandon Nimmo bruised his left hand during an at-bat in Philadelphia, and three days after he last appeared in a game, the Mets opted to place Nimmo on the injured list. The move is retroactive to May 3, meaning Nimmo won’t be eligible to return until the Mets open a three-city road trip in Tampa on May 14.

Nimmo said he felt like his hand “exploded” when he fouled off a 97-mph Zack Wheeler fastball last Saturday at Citizens Bank Park. Subsequent testing revealed a bone bruise in his left index finger, which the Mets considered serious enough to keep Nimmo out of the starting lineup the following day -- but not enough for them to place him on the IL at that time. Instead, Nimmo played center field as a defensive replacement on Sunday night.

“I don’t think it’s going to be long-term,” Nimmo said that afternoon. “I think when we look back on this in the scheme of the season, it’s going to be a little blip. But obviously, I hate to miss any games, and it’s very, very frustrating for me because I try to prepare for these things.”

Yet Nimmo was not physically ready to play in either game of the Mets’ doubleheader Wednesday in St. Louis, prompting the move. A series of tests revealed that he still could not swing without pain.

“He just still feels it,” manager Luis Rojas said. “He’s not able to hit … so the usage is just limited.”

Nimmo was the Mets’ best hitter early in April, batting .408 with a .491 on-base percentage over his first 14 games before more recently dipping into a 1-for-17 slump. In Nimmo’s absence, Kevin Pillar will play center field with some help from Albert Almora Jr. The Mets promoted catcher Patrick Mazeika from their taxi squad in time for Game 2 of their doubleheader against the Cardinals on Wednesday, in part because they have run out of experienced position players for their bench. In addition to Nimmo, J.D. Davis and Luis Guillorme are also on the IL.

Given how close Nimmo came to avoiding the IL, it’s likely he will return as soon as he’s eligible. In the interim, the Mets will rely extensively on Pillar, who subbed in for Nimmo on Saturday and has since started four consecutive games. Playing consistently helped Pillar break out of a 3-for-26 stretch to start the season; he homered on both Sunday and Monday as part of consecutive multi-hit efforts.

“It’s just a big difference when you get a chance to start, you get to kind of settle in,” Pillar said last weekend. “Sometimes when you pinch-hit, you feel like the only way to be successful is to get a hit, as opposed to just having a good at-bat. I think when you get a chance to start and you know you’re going to get three, four, five at-bats per game, it allows you to kind of settle in.”

Mazeika spent three separate stints with the Mets last season, but never appeared in a game. He has yet to make his big league debut.