DENVER -- It’s easy to separate the burly pitcher in Oklahoma crimson who put all his pounds into his triple-digits fastballs from the lean dude in purple pinstripes who depends on leverage and timing. But they're the same guy: Rockies right-hander Jon Gray.

“It’s been piecing together lots of things, kind of evolving as a pitcher,” Gray said. “I’m nothing like I was when I was signed. I mean, I think I’m still a power pitcher, but the way I use my stuff is totally different.”

Gray will continue what has been a winding evolution on Saturday night. He will make his first start of 2021, a pivotal career year.

After being drafted third overall in 2013, Gray has been the icon of a Rockies pitching era that included consecutive postseason trips in '17 and '18. But along the way, he’s also been injured, thrived, struggled again, changed and thrived, and been hurt again. Those are just the changes that can be deciphered from the back of the baseball card.

Gray is eligible for free agency at season’s end. He’s not like two other Rockies stalwarts -- shortstop Trevor Story, due for untold riches (considering Francisco Lindor’s 10-year, $341 million contract with the Mets) and outfielder Charlie Blackmon, who can stick around due to player options he holds for the next two winters.

Gray, on the other hand, had a 6.69 ERA in eight starts as part of a 2020 campaign that was affected and shortened by a right shoulder injury. Even if Gray rebounds to the level of '19, when he fanned 150 in as many innings before a left foot stress fracture ended his year, he could join Story as trade fodder if the Rockies struggle.

Gray, though, is on a detailed enough process of self-improvement that he is trying to freeze out what he doesn’t control.

“I’m just trying to focus; everything's a blessing,” Gray said. “Even the bad days, even just being in the uniform -- and it could be in the worst day ever -- it’s great. It’s a great day.”

Gray loves learning.

Upon being drafted, he asked Rockies coaches to help him remake his motion, since he wasn’t always going to hit triple digits.

Over the years, his motion no longer involved as much of a rock toward first base. He also used to like the horizontal break on his slider. But in 2019, when he decided to “trick myself into thinking I’m throwing a fastball," horizontal break lessened -- but the pitch became more effective.

Gray went to the Driveline performance facility in suburban Seattle for workout ideas, and did strength training with Denver Broncos strength and conditioning coach Loren Landow after the 2018 season, when he posted a 5.12 ERA and was not put on the postseason roster. Gray emerged stronger in '19, before his foot injury flared in August.

Last season, the shoulder pain led to a drop in his average fastball velocity, from 96 to 94 mph. Possibly worse, Gray could not figure out how to pitch without his higher-end velo.

So, more changes this winter.

Gray eliminated some shoulder exercises and added others. The owner of a home in Scottsdale, Ariz., he worked out in his home gym. Detailed bloodwork has led to an adoption of nutritional supplements. A complete physical workup revealed a connection between foot stress fractures in 2016 and '19, and last year’s shoulder problem. Gray underwent acupuncture treatments, which he said continue during the season. He’s also vowed to lessen his throwing between starts.

Mental skills are another constant search for Gray and Rockies mental skills coordinator Doug Chadwick. They settled on an audio track, narrated by someone who does a reasonable Morgan Freeman impression. He has also learned to recenter himself by focusing his attention on the pole holding the American flag. All figured into his strong 2019.

The need to address such issues flared last year. Gray said his shoulder issues dragged him down to the point where he felt he couldn’t help the team in any form. While he thinks the best solution is the return of his velocity this spring, Gray must fight the fight for better emotional control.

“I still have the audio file,” he said. “Lately, I’ve been doing my own thing -- run different scenarios through my head when I’m breathing. I know it sounds weird, but it really helps me feel like I’ve been out there already.”

It was so much easier when Gray could put his body behind 100-plus mph fastballs every single start, the way he did his junior year at OU.

“It would be a lot easier,” Gray said with a chuckle. “But it’s kind of fun, really. The journey’s kind of fun.”

Updates:

• Rockies manager Bud Black said he hasn’t determined if Germán Márquez or Chi Chi González will start Tuesday’s opener of a three-game set with the D-backs at Coors Field. In Thursday’s opener against the Dodgers, Márquez walked six, gave up six hits and threw 92 pitches in four innings. González threw 42 pitches in two innings of relief.

• Black said there is no timetable for a return for left-hander Kyle Freeland, who sustained a left shoulder strain March 23, but he is progressing with strengthening exercises.