About a month and a half ago, Adam Eaton had just torn a knee ligament. Now, he is walking. (Nick Wass/Associated Press)

Adam Eaton used crutches to wander into the Washington Nationals‘ clubhouse on Sunday afternoon, though he said he didn’t know why he was using them, since he didn’t really need them. He made his way to the back of the clubhouse, to the cubbies in the middle where players can find their mail.

“Yes!” he said, as he opened a set of Mighty Mouse stickers ordered for the scooter he used to need, but doesn’t anymore. Eaton says he can walk “pain free” now and is getting full extension in that surgically repaired left knee.

“I’m ahead of schedule,” Eaton said, sitting in the dugout before the Nationals’ late afternoon game against the Rangers, about seven weeks after tearing his anterior cruciate ligament and meniscus.

“Can’t really put weeks on how far ahead of schedule we are, but we’ve been weight-bearing for four or five days now,” Eaton said. ” … it’s been an experience, that’s for sure, but everything’s going in the right direction.”

Eaton’s typical game day includes arriving just before batting practice, when the training room is starting to clear of players whose needs are more imminent. He works through therapy and then cools down, normally just as the game is beginning. When the team is on the road, Eaton shows up earlier, working six days a week. He estimates that he undergoes three to four hours of therapy a day.

“I thought there was going to be a lot of physical therapy involved, but really there’s been a lot of occupational therapy involved. Relearning how to bend it and use it in space,” Eaton said. “I’ve never really had an experience where I tell my leg to lift and it doesn’t lift. It’s really a surreal experience. I have to conscientiously tell my quad to contract to hold my knee and knee in place.”

Center fielder Adam Eaton attempts to reel in a deep fly ball during healthier times, in April, against the Phillies. (Jonathan Newton/The Washington Post)

The 28-year-old hadn’t given updates on his progress since the immediate aftermath of the surgery and seemed eager to do so for the first time Sunday, citing the need to stay in touch with reporters and keep everyone posted on his progress. When pushed about the specifics of the extent of the injury, including what exactly doctors found when they got in his knee, how he chose a patella graft over hamstring or quad grafts, and things like that, Eaton bristled. He asked reporters to “keep it positive,” and did not answer the question.

His sensitivity on that point stood out amid his calculated optimism about the rest of his rehabilitation, the “silver lining” of increased appreciation for the game, the things he learns by watching games, and even the guilt he feels about not being on the field.

“I hope my presence here is felt, just in the sense that I’m dedicated to them just as they’ve been dedicated to me,” Eaton said. “The trade this offseason probably wasn’t the most popular one, but I love this city. I love the people within the organization. I love everyone that’s involved. And I want to return the favor: You’ve invested time in me and effort, and that’s what I want to do.”

He hopes that effort will pay off in a return to full strength, though that will likely come in 2018, and not this season. With a 2017 return unlikely, Eaton said his mind sometimes wanders to the big picture.

“Not just this year, not just next year, but the longevity of my career and how it may be shaped by this injury,” Eaton said. “But I try to stay positive in the sense of longevity, this year and next.”

Without Eaton available in May, and with Michael A. Taylor handling most of the duties, Nationals’ center fielders compiled an .830 on-base plus slugging (OPS), eighth best in baseball.