The Rockies’ most perplexing starting pitcher in 2018 is also one of their biggest question marks of 2019.

That player is Jon Gray, the right-hander whose roller-coaster season ended up with him being left off the Rockies’ playoff roster. It was a tough blow for Gray, who finished with a 5.12 ERA (up drastically from his 3.67 ERA in 2017) and served up a career-high 27 home runs.

Theories abound about what went wrong with Gray, including evidence that he crumbles under the pressure of big games. Gray, however, offered up a different reason.

“I wasn’t really healthy,” Gray said. “My (velocity) was down this year. I was down about 20 pounds this year. I need to get back to 230-235.”

Asked if he was battling an illness, Gray answered: “Maybe, I’m not sure. My body kind of did a 180 (degree turn) this year and I’m not sure why. I want to get it back under control and get back to being strong.”

He plans to do that by hitting the gym and packing on muscle.

“I want to have the best offseason of my life, get huge physically, that’s what I was missing this year,” Gray said. “I wasn’t me. It’s tough to compete like that. I don’t want to ever have to do that again, I want to go out there strong every time, so I’ll start with that. That’s my main goal.”

Gray certainly had some fine moments this past season. In the Rockies’ 10-1 victory over Philadelphia on Sept. 24, he gave up one run on four hits and struck out seven across seven innings. But then came his last start of the season against Washington in the penultimate game of the regular season.

A victory would have kept the Rockies in the lead for National League West title with one game to go, but Gray lasted only two innings, allowing five runs on seven hits. Colorado lost 12-2 and ended up in a tie with the Dodgers and eventually lost the division title in the Game 163 tiebreaker. That performance cemented Gray’s fate and he didn’t pitch in any of Colorado’s four postseason games.

“I’ve thrown a lot of big games for this club. It’s just that, when things are shaky, I don’t know what to expect out of myself,” Gray said.

Asked if the pressure of the moment overwhelmed Gray, manager Bud Black skirted the question. “This was a matter of a bad location more than anything,” Black said.

Gray, eager to embark on his offseason program, said things will be different next year.

“I know a lot of (crud) has happened this year,” he said. “It’s been a rough, rough year for me. I can’t wait to prove everybody wrong and show what I’m all about.”