After Jerad Eickhoff was humbled last summer, he would stand in front of a locker in Georgia or California and proclaim he could handle it because of his mental toughness. He labeled his season "a grind" again and again while team officials indicated he never appeared on the club's internal medical report. But something was amiss.

The 27-year-old righthander did not pick up a baseball for more than two months — from the time he exited in the third inning of a game last Aug. 30 until November. He has studied the mechanical flaws that mounted to produce uneven results and increased strain on the front of his shoulder. He missed the final month because of nerve irritation in his right hand.

This week, in town for promotional events, Eickhoff stood inside the home clubhouse at Citizens Bank Park and pondered how much of his 2017 season was affected by physical limitations.

"A lot of it was," Eickhoff said. "I think, honestly, what kept it moving was my mentality. That was one of the hardest things I have had to do — to pull myself out of the game. But it's going to make me a better pitcher because of it."

The Phillies know what kind of person Eickhoff is — the kind willing to pitch through an ailment. The Phillies remain unsure about what kind of pitcher Eickhoff is — he was not the heralded arm contained in the Cole Hamels trade, but his 2016 season generated optimistic projections of a potential No. 3 starter. His 2017 season altered the immediate outlook, although it is difficult to imagine a 2018 rotation combination that does not include Eickhoff.

Club officials are hesitant to add several starting pitchers to a muddled rotation because they harbor hope that one or two of their young arms will advance in 2018. The issue is this: Are the arms advancing from a No. 5 to a No. 4, or more than that? The mid-rotation labels applied to Eickhoff after his breakout 2016 season were ambitious. But 197 innings of a 3.65 ERA from a 25-year-old pitcher can make talent evaluators giddy in this current version of baseball.

The Phillies will cling to the chance Eickhoff — healthier and smarter — recaptures it.

He has thrown from a mound three times this winter. Eickhoff said it has been a "fairly normal offseason," the exception being a December trip to Florida for an appointment with team doctors and athletic trainers.

He believes his mechanical flaws were the cause of the nerve injury, not vice versa.

"Over the course of a season, it built up and built up," Eickhoff said. "It just kept putting strain on it. Over the course of time, something had to give. My muscles got a little weak."

Eickhoff has filmed his throwing sessions this winter and sent the video to Rick Kranitz, the Phillies' new pitching coach. He has applied mechanical adjustments — "slightly noticeable things" — that include his hand placement and a more fluid motion designed to prevent his body from opening too soon. The proof will be in May, June and July.

Eickhoff's quest for a more effective fastball is paramount. His curveball is his best pitch. His slider is a fine third offering. But he will need an improved fastball, not just in velocity. The quality of the pitch — location and movement — was just as debilitating as the dip in speed. Opponents crushed it in 2017.

Jerad Eickhoff’s Fastball by the Numbers
2015 .243 .467 91.6 58.1 3.0
2016 .294 .489 91.6 52.5 2.4
2017 .341 .516 90.3 49.2 2.5

The Phillies are hopeful some of their inexperienced pitchers can improve based on new perspectives, both from coaches and analytics, added this winter. Eickhoff is a cerebral pitcher; he prepared more behind the scenes with video and data than any other Phillies pitcher last season. The Phillies will challenge their players in 2018 with different ideas to prepare.

Manager Gabe Kapler, in his makeshift bare-walled office that is scheduled for a renovation before the season begins, recited advanced metrics Tuesday such as fielding independent pitching (FIP) and batting average on balls in play (BABIP) from his iPad to help explain Eickhoff's slide in 2017.

It is, Kapler acknowledged, an incomplete picture.

"We are trying to balance this very objective set of information," Kapler said. "It's absolutely true — everything I just said, reading off a public-facing site. Then, there's what we see observationally. We're just not to the place where this new staff has had a chance to observe. It's a critical part of the conversation. Sure, we want to evaluate based on what happened last year. But, much more consequently, we want to combine that information with our experience. What does this person look like on the mound?"

Kapler and Eickhoff could bond on a shared analytical view of the game. Asked about the rotation puzzle to be decided in spring training, Eickhoff spoke with a tone that would excite Kapler, the intense rookie manager.

"I say it every year, and I truly mean it: I compete for a job every year," Eickhoff said. "That's not a given. That's not something that is handed over to me. I see that going into my training and my thought process now in these bullpen [sessions]. There's intent to everything. There's a way I go about it and a reason I do that. That's why.

"It's going to be competitive, and it's going to breed a positive end result."