The Curve third baseman was coming off a two-day, 0-for-10 spell. He felt his body hit a wall. And for one of the first times in his life, Walker didn't have an answer.
"I just remember being as tired as I've ever been and thinking, 'How did that happen?'" Walker recounted recently. "It just got to the point where my tank went on empty and it was hard to get it back on even half full."
He never did.
Walker had been rolling through the season at Double-A Altoona up until that point. Before those taxing few days in Harrisburg, which were soon followed by an even more draining 1-for-24 rut, Walker seemed to be poised for an accolade-laced season.
He had been selected to start at third in the Eastern League All-Star Game. His batting average had peaked at .319 in mid-June, a month in which he hit .363 during its entirety. Essentially, behind Andrew McCutchen, Walker was becoming the prospect in the system.
Not to mention, the fact that Walker hails from Pittsburgh made the story that much more perfect.
The transition from catcher to third baseman -- which began last Spring Training -- had been bumpy at times, but the hitting, well, that was always a constant. That is, until that point in late July.
"It was 'Bam.' I just hit a wall," Walker said. "You sometimes feel like that during the season, but in this case, it was day in and day out."
It's with that memory that Walker arrived in Bradenton this spring, eager to begin his second full year as a third baseman. He had heard the pointed challenges from the new management team that saw conditioning (or a lack thereof) as having a direct correlation to Walker's late-season offensive slump.
"He needs to take a little more time to make sure he is in shape to be ready to play an entire season through October in strong form," was how general manager Neal Huntington put it.
However, ask Walker if he thinks the problem was a lack of conditioning and the multi-sport high school athlete will take a little bit of offense to even the suggestion that he is not in adequate physical shape.
"That's something that ..." Walker stopped.
He started over.
"I've worked very hard to get to where I'm at," he said. "All of a sudden, I hear that that's the reason I'm not finishing strong. I don't want to say that's not the case, but there are a lot of different factors."
Walker said he believes that it was overworking himself into peak shape -- rather than not being in good enough shape -- that led to the collapse.
As a result, Walker altered his offseason workout regimen this past winter. He cut back from spending seven days a week in the gym in order to make sure his body could adequately recover. Wednesdays became an off-day this past offseason, as did most weekends.
"This year, as painful as it was for someone who loves to do things and likes to work hard, it was tough for me to take time out," Walker said. "That was something that I forced myself to do."
The organization also stepped in to direct Walker on better ways to prepare himself to be physically ready for an entire season.
"We have talked to him in terms of what he needs to do to move to the next spot," said Kyle Stark, the Pirates' director of player development. "Every player goes through getting the knowledge of how to get through a whole season. It's one of those things that each guy has to figure out what works best carrying himself into the season and then through it as well."
Between the changes in his conditioning habits and the fact that he has an entire season of playing third base now under his belt, Walker has plenty of reasons to be encouraged going into a new season. It's all but set that Walker will begin the season in Triple-A, though he's getting closer to the point of being Major League-ready.
"Neil's been doing well," said manager John Russell. "He's got a good presence about him on the field. He's come a long way."
Entering Friday's action, Walker had gone 5-for-16 in Grapefruit League games so far. Even more encouraging, though, may be the fact that he has looked adequate at third so far this spring after committing 27 errors there in 136 combined Double-A and Triple-A games last year.
He insists he feels better there, too.
"You can take as many ground balls at third as you want, but the moment the ball comes off the bat in a tie game, it's almost like it is completely different," said Walker, who played all but 19 games last season in Double-A."I think the big thing was the confidence level. I didn't know what to expect. I didn't know what was going to happen."
Part of the work that still needs to be done is mental, making sure that one bad stretch doesn't steamroll into becoming one bad month, as it did last year. Part of it is position-related, with certain nuances to playing third base -- like getting a quicker first step -- still needing to be mastered. And part of that work is obviously rooted in physical conditioning.
But at least for now, Walker feels he has the right knowledge and guidance to get him there.
"I truly believe that I'm prepared to play at that next level," Walker said. "But at the same time, I'll see some of the other third baseman in the league and I'll say, 'I don't feel like they look.' There is still a lot to learn about where I need to be."
Jenifer Langosch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.