Nick Maton began his major-league career in the Phillies’ starting lineup for 17 straight games and spent his first month in the big leagues playing nearly every day. He held his own, hitting .313 through his first 22 games, all but four of which he started.

Maton was the pleasant surprise of the team’s tepid start to the season. But now the 24-year-old is struggling to simply crack Joe Girardi’s lineup.

Maton, a left-handed hitter, sat again Tuesday even though the Phillies were facing Cincinnati right-hander Sonny Gray. Maton has started just two of the team’s last nine games.

Girardi cited Gray’s splits this season against right-handed hitters — they have an .802 OPS as opposed to .596 by left-handers — and the fact that Ronald Torreyes has two career plate appearances against Gray. Torreyes homered off Gray in the third inning, his first homer since 2017.

“Stay tuned for tomorrow,” Girardi said regarding Maton.

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Maton’s last multi-hit game was his two-homer effort May 16 against Toronto. Since then, he has totaled just 22 plate appearances. Maton has cooled off as he has nine strikeouts and one hit over that span, but his playing time has nearly disappeared.

If Maton starts Wednesday, it will be just his sixth start in 15 games since his two-homer day. Torreyes, a 28-year-old utilityman, has started nine times since that game.

“I think it’s growing pains that a young guy goes through, but overall he’s played pretty well for us,” Girardi said. “But Torreyes has played really well, too.”

Phillies now see Moniak in left or right

Mickey Moniak has spent most of his time in triple A this season playing center field, but the Phillies now see the first overall pick in 2016 as a corner outfielder.

“I think when you look at prototype center fielders, he probably doesn’t have the speed of a lot of them,” Girardi said. “I would not be afraid to run him out there every day. I would not be afraid to do that.”

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The Phillies could have promoted Moniak when Roman Quinn tore his Achilles tendon, but they instead opted for veteran center fielder Travis Jankowski. Moniak has struggled offensively at triple A and Girardi said Sunday that the Phillies “envision Mickey more as a corner outfielder than a center fielder.”

“I think that’s maybe where we see him,” Girardi said Tuesday. “I mean, he can play center. I don’t have a problem putting him in center, but with the way our team is constructed, I’d probably stay with Odúbel [Herrera] there. You kind of look at the construction of your team and what possibly opens up in the future and those sorts of things.”

Harper, Gregorius make progress

Bryce Harper and Didi Gregorius each swung a bat on Tuesday for a second straight day, which is significant progress for their return from the injured list.

Gregorius (right elbow impingement) last played on May 12 and Harper (left forearm contusion) has been out since May 22. Gregorius will likely need a rehab assignment before returning, but it is uncertain if Harper will.

“Each one is a progression where each day you kind of hope that they feel good the next day,” Girardi said. “The returns coming in today were pretty good. So a little bit more.”

Extra bases

Girardi said the Phillies are considering using a four-man rotation in June as they have seven scheduled off days. It would be a way for them to give extra starts to Aaron Nola, Zack Wheeler, and Zach Eflin. ... Shortstop Bryson Stott, the team’s first-round pick in 2019, was promoted Tuesday to double-A Reading. He hit .288 with a 1.001 OPS in 22 games with high-A Jersey Shore. ... Scott Kingery, on the injured list with a concussion, started a rehab assignment with triple-A Lehigh Valley. He is expected to stay with the IronPigs after his rehab is finished. ... Spencer Howard will start Thursday afternoon’s series finale against Reds right-hander Vladimir Gutierrez.