NEW YORK -- Ten days after sending struggling starting pitcher Adrian Houser to the bullpen, the Mets are shifting him back into the rotation.

Manager Carlos Mendoza announced Monday that Houser will start Wednesday’s game in Philadelphia, which will mark the veteran right-hander’s first start since May 2. In the interim, Houser made a lone relief appearance last Friday against the Braves, throwing two scoreless innings.

“He’s still built up,” Mendoza said. “We’re trying to find that extra day of rest for some of the guys. He’s ready to go.”

The move means the Mets will go at least one turn through their rotation with six starting pitchers. The team used a modified six-man rotation often last season, inserting a spot starter during long stretches without a day off to give everyone else an extra bit of rest. By pitching Houser on Wednesday, the Mets will ensure that additional day for Luis Severino, Jose Quintana and others.

After that, the schedule is unclear. Tylor Megill (right shoulder strain) is physically ready to come off the injured list and will be rested enough to do so by Friday. But Mendoza would not commit to a Major League start for Megill. Instead, the manager indicated Megill could make another rehab start, join the bullpen or stay at Triple-A Syracuse on a Minor League option.

“Everything’s on the table here,” Mendoza said.

Asked specifically if Megill is a bullpen possibility, Mendoza replied: “That’s some of the discussions we’re having -- whether he’ll make another outing, or we’ll put him on our roster.”

Megill was dominant over his last two rehab starts, striking out 13 batters over 9 1/3 scoreless innings. In the past, Mets officials have cited his value to a big league rotation when asked if he might ultimately become a reliever.

Now, however, Megill’s fate could hinge upon Houser’s ability to succeed back in the rotation. A return to top form for Houser could give the Mets pause when considering their next steps. But if Houser struggles, as he did in producing an 8.16 ERA over his first six starts, Megill might be able to crack the starting six.

And yes, it is a six-man rotation (sort of)
Mets officials won’t call this a traditional six-man cycle, because they don’t want to create a long-term scenario in which their regular starters are frequently going a week or more between outings. But for now, at the beginning of a stretch of 26 games in 27 days, the Mets can conceivably use six starters for multiple turns apiece.

“It tends to help guys more than it hurts guys to give them that extra day,” pitching coach Jeremy Hefner said last week. “That’s kind of why we landed there.”

More complicated decisions could surface in the future, when David Peterson (recovery from left hip surgery) and Kodai Senga (strained right shoulder capsule) are ready to come off the injured list. But Peterson isn’t eligible to return until May 27, and Senga’s recovery will almost certainly bleed into mid-June or beyond.

Senga’s “unique situation”
Once Senga does return, the Mets intend to give him an extra day of rest as often as possible, making the six-man rotation an even more common sight. But his return could still be a month or more in the future. Speaking Monday for the first time since he paused throwing live batting practice sessions, Senga said he wants to perfect his mechanics before proceeding because “the reason why I ended up getting hurt was partially due to mechanics.”

“With my current mechanics, I didn’t think I’d be able to come back at 100 percent,” he added through an interpreter. “So I’m taking a little bit of time to look over everything, making sure everything is perfect before I get back into games.”

Part of Senga’s delay is due to the fact that he’s accustomed to Japanese rehab culture, which offers players freedom to dictate their own schedules. While that’s not typically the case in the United States, the Mets are giving Senga wide latitude to set his own pace.

The right-hander has taken advantage by stepping backward in his rehab after advancing as far as live batting practice sessions in late April. Senga threw a 45-pitch bullpen session on Sunday, according to Mendoza, and will throw another on Wednesday. But neither he nor the Mets have a firm timetable for him to face hitters again, go on a Minor League rehab assignment or ultimately come off the IL.

“It’s a unique situation,” Mendoza said. “I’m trying to learn the individual himself. … It’s fluid. It’s flexible. We’ve just got to listen to the player.”