PHILADELPHIA -- Matt Vierling has played well since he rejoined the Phillies last week. Odúbel Herrera has played well most of the season.

So on Tuesday the Phillies optioned struggling outfielder Mickey Moniak to Triple-A Lehigh Valley. They selected Yairo Muñoz’s contract from Lehigh Valley to take his place. Muñoz started at second base Tuesday night against Miami.

“We just want him to go down and get his swing back,” Phillies interim manager Rob Thomson said about Moniak. “Mickey is a big part of this club and in the future.”

Moniak batted .160 (4-for-25) with one RBI, three walks, 11 strikeouts and a .410 OPS in nine games since he returned from a fractured right hand. Herrera and Vierling, meanwhile, work better as a traditional platoon in center field. Herrera hits left-handed; Vierling hits right-handed.

“It’s a little better fit for us,” Thomson said. “And it’s probably the best thing for Mickey right now, just so he can go down and get consistent at-bats and get his swing back.”

Herrera is batting .276 with five homers, 15 RBIs and an .815 OPS in 39 games. Bryce Harper (1.008 OPS) is the only Phillies batter with a higher OPS (minimum 40 plate appearances). Vierling opened the season with the Phillies before struggling and being optioned to Triple-A in May. Since he rejoined the team last week, he is 3-for-9 with a game-winning home run on June 7 against Brewers closer Josh Hader and a big stolen base with two outs in the ninth inning in Monday night’s walk-off victory over the Marlins.

Vierling has shown his versatility defensively, too. He not only can play everywhere in the outfield, but in the past few days he played second base for the first time in his career and third base.

“He’s got a lot of value to us,” Thomson said.