Zach Eflin started his offseason throwing program a month earlier this winter than he normally does. The Phillies right-hander completed his first bullpen session three weeks earlier than usual and this week logged his 10th session, six or seven more than he would traditionally have thrown by the start of spring training.

Every major-league pitcher will be challenged this season to carry their arms through a six-month season after playing last summer for just nine weeks. Baseball’s return to a 162-game schedule — 100 more games than in 2020 — will test pitchers more than anyone else.

Eflin made just 10 starts in 2020 but eyes 30 this year. If so, he would need his arm to log roughly 104 more innings than he did last season. It is a challenge every pitcher will have to face this season. And that’s why he started early.

“I can see it being a challenge for people that might be a little worried about it, but personally I’m not worried about it,” Eflin said. “I’ve always been a guy where I’ve always wanted the ball. So I’m just going to stick with that. I don’t think it’s going to be too much of a deal for me personally because I feel like I’ve done enough in the offseason to prepare to make that next step from five-plus innings to however much this year. So I feel like I’m in a good position and really ready to rock and roll.”

» READ MORE: Phillies will use a five-man rotation, but two spots remain up for grabs

The Phillies had considered employing a six-man rotation this season to alleviate the increased workload, but manager Joe Girardi said Friday that the team will continue to use a traditional five-man rotation. The Phillies, Girardi said, could insert a sixth starter if a need arises or if pitchers tire, but they are planning for five.

Eflin, who will be the team’s No. 3 starter, said he wants to pitch in a five-man rotation. The starters, he said, are “going to kind of coast right into it and it’ll just be like every other year.” Aaron Nola said earlier this week that he, too, would rather pitch on normal rest than benefit from an extra day by having a six-man rotation.

“It’s what we’re all used to, it’s what I’m used to,” Nola said. “I want to make 33-plus starts a year. This year, too. That’s always been my goal, I want to throw, get past the 200-inning mark and 30 starts every year. That’s kind of what I try and prepare my body for.”

Nola made 12 starts last season and threw 131 fewer innings than he did in 2019. But Nola said he did not change much this winter, approaching the offseason the same way he did following a normal season. It will be quite a jump for Nola to log 34 starts and 202 innings — which he did in 2019 — but he believes it’s possible.

“I think we’re ready for that,” Nola said. “And I think … a lot of us have worked really hard to keep our bodies in shape and keep our arms in shape to handle that load.”

Eflin finished last season with a 3.97 ERA, appearing to take the next step in becoming a rotation staple. He struck out 10.7 batters per nine innings, a spike of more than three strikeouts per nine innings. His curveball became a key part of his arsenal and Eflin looked like a complete pitcher.

» READ MORE: Jeff Mathis, 37, could be Phillies’ backup plan if J.T. Realmuto’s injury is significant

But his season was defined by his final two starts, two crucial wins that kept the team’s postseason hopes alive: He pitched a seven-inning shutout against Toronto and pitched into the ninth inning against Washington. Eflin was pitching his best at the season’s end. If he can do that again this September, this time after a 162-game season, his early start this winter will be worth it.

“What I expect from Zach is to build off of last year,” Girardi said. “I thought he had a really good year for us and I think he can even be better. I think he used his curveball a lot more effectively last year. Down the stretch, he pitched brilliantly for us. I don’t want to put a limitation on him because I think his stuff is that good that he can continue to grow and grow and grow. I look at us that we have a 1A and 1B [Nola and Zack Wheeler]. We could have a 1C. That’s how I feel about Zach Eflin. I’m excited about his year and really look forward to getting it started.”