"There's a lot of theories," Yankees general manager Brian Cashman said. "He came in physically built stronger. He hit the weights pretty strongly. Did that affect him one way or the other? I know that through [pitching coach] Larry [Rothschild] and our strength coach, we told him this winter that he needed to stay more flexible and stay off the bulk."
A major factor in Severino's performance dip was that he appeared to lose the feel for his changeup, reverting to using mostly a fastball-slider combination. The Yanks pushed him to throw the changeup more when he returned to Triple-A Scranton/Wilkes-Barre in late May, but he acknowledged that his confidence in the pitch was shaken.
"No one knows why one particular year he woke up and lost the feel for that changeup," Cashman said. "So we'll see. Even with all of those theories, he showed up in Spring Training, and there was one game against the Tampa Bay Rays -- he looked like a Cy Young Award candidate.
"All I know is we're certainly hopeful he stays in the rotation for his career, because that's what we need."
Severino will turn 23 in February and is among a group of candidates for the final two rotation spots, joined by Luis Cessa, Chad Green, Bryan Mitchell and Adam Warren. Cashman also mentioned right-hander Chance Adams, the Yankees' No. 14 prospect according to MLBPipeline.com, as a dark-horse contender.
Although Severino was excellent out of the bullpen last season, posting a 0.39 ERA with 25 strikeouts over 11 appearances, his preference would be to take the ball in the first inning.
"The bullpen is a great role, but in my mind, I want to be a starter, because I've always been a starter and I like it," Severino said late last year.
That syncs with New York's view that the best course of action will be to offer Severino more chances to succeed as a starter.
"It's way too early to tell," Cashman said. "He has all the equipment to be a starter. Last year was really the first year where he lost his changeup. He never had it from start to finish. As long as he turns the clock back as early as 2014, '15, then '16 is really an aberration.
"It's something he's always been and he's always been successful at. He never really finished off his development because of our needs at the big league level. We plan on continuing it."