PHILADELPHIA — Kodai Senga’s final start of his rookie major league season is scheduled for Wednesday at Citi Field.

The Mets right-hander, barring a complete game, will finish at or just under the 170-inning cap that organizational officials had implemented for the season.

To make that to happen in a season in which the 30-year-old Senga remained healthy, extra days of rest routinely were added between the pitcher’s starts.

The dual purpose was allowing Senga to mimic his routine in Japan, where he pitched every seventh day.

It has been a juggling act for the Mets, but one that has proved successful.

Senga, who was fourth in MLB with a 2.96 ERA and fifth among pitchers with a 4.4 bWAR as play began Saturday, will likely receive Cy Young and Rookie of the Year votes, and potentially will be a bargain on the five-year contract worth $75 million he signed last winter.

One question that will be examined this offseason by the Mets is whether to keep the same routine with Senga between starts, maintaining the extra rest, or whether a traditional approach can work for him next year.

“It’s a very fluid situation,” Senga told The Post through his interpreter. “It’s not just, ‘We want you to go on four days’ rest or not.’ There is a lot of thought that goes into that decision on the team’s end too, so I think they will prioritize my health as they did this year. We’ll do my measurements between starts as we did this year, and if everything looks good sometimes it will happen, sometimes it won’t.”

Among the factors that will be considered, according to pitching coach Jeremy Hefner, are which pitchers the Mets might add this offseason. Senga and Jose Quintana are the two proven commodities returning, but beyond that there are holes that need to be filled.

“We’ll try to do what’s best for Kodai but also the rest of the group, too,” Hefner said before the Mets’ 7-5 loss the Phillies on Saturday night in Citizens Bank Park.

The Mets have employed a six-man rotation for this final stretch of the season. It’s a tactic that could be used on a regular basis next season, especially if the Mets were to sign another Japanese pitcher — the team’s pursuits could include 25-year-old right-hander Yoshinobu Yamamoto, who is expected to be posted by his team, the Orix Buffaloes, after this season.

But implementing a six-man rotation also would mean working with a shorter bullpen. It has been less noticeable for the Mets during this stretch because of the expanded September rosters.

As Senga prepared for his 29th and final start of the season, he was asked about his fatigue level.

“It’s more of a mental fatigue,” he said. “Given the situation that the team is in with our playoff chance diminished and having to pitch through that kind of circumstance of not being able to make it is tougher on you mentally rather than physically.”

Hefner said he would have gladly signed on before the season for what the Mets have received from Senga, whose “ghost fork” has lived up to its billing as a dominant pitch.

“There weren’t really any major overhauls,” Hefner said. “He got away from the sweeper at the beginning of the year and focused more on the cutter and the split [ghost fork] has been an unbelievable pitch — one of the best pitches in the whole game — so definitely I would have signed up for that.”

Senga’s satisfaction, as much as anything, comes from knowing he didn’t miss a day of work.

“Staying healthy was the biggest priority,” Senga said. “As long as I was able to stay healthy it’s one objective cleared.”