SCOTTSDALE, Ariz. -- If the underlying reasons behind the 2020 struggles of two key bullpen members are in the past, manager Bud Black can feel better about the present.

Right-handers Carlos Estévez and Jairo Díaz were supposed to make other clubs envious of the Rockies last season. But after starting the season strong, Estévez took a comebacker to the hand. Díaz had solid early numbers, but a lack of sharpness -- a result of missing time because of a COVID-19 diagnosis at the start of Summer Camp -- eventually caught up with him.

• Rox may have formula to defy projections

Black led the Rockies to the postseason in 2017 and 2018, despite working with a questionable offense, by juggling solid starting pitching with a mass of effective bullpen options. Could Estévez and Díaz -- and possibly other, less-proven arms -- join such veterans as closer Daniel Bard, Mychal Givens and Scott Oberg (back from surgery to relieve blood clots in his arm) and help Black revisit his proven method?

“We can’t afford to have three or four guys in our bullpen have off years,” Black said. “We saw that last year, and we saw the results of that. Those two guys are extremely important. Hopefully we look back at the end of October and say Carlos and Jairo had great years, just like they had in 2019.”

Although the Rockies would love some less-heralded relievers to push into trusted roles, the spotlight shines a little brighter on Estévez and Díaz because of their histories. Both have served as closers -- Estévez as a rookie in 2016, Díaz at the end of ’19 -- with some success.

Estévez established himself with solid work in late 2017 and then, after he missed ’18 with a strained oblique and then strained his right elbow during rehab, struck out 81 in 72 innings in 2019.

But whatever success he had early last season dissolved not long after a liner off the bat of the Rangers' Scott Heineman hit his throwing hand on Aug. 16.

Through Aug. 25, Estévez had a 2.25 ERA, struck out 13 against four walks and held opponents to a .419 slugging percentage. But from Aug. 29 to season’s end, opponents blitzed him for a .905 slugging percentage and slapped him with an 18.00 ERA.

“My day was really long,” said Estévez, whose hand still shows swelling, although he feels no pain. “I had to get a heat pad on my hand, get a small massage to get the fluid down because it was always swollen. And I lost my slider -- I was getting impingement on my fingers every once in a while.

“We’ve got that out of the way. We’re good to go this year.”

Díaz established his Major League career over 56 outings in 2019, with 63 strikeouts in 57 2/3 innings and scoreless ball in seven of his last eight appearances. After the pandemic shutdown and his COVID diagnosis, the Rockies used him as they originally planned, in late-game relief. He was even the first option as closer after Wade Davis.

Through his first seven games, Díaz had a 1.35 ERA, but opponents had a .355 on-base percentage, and his outings included numerous great escapes. His pitch location was poor, and he couldn’t keep from telegraphing his fastball with faster mechanics and his slider with a slowed motion.

But on Aug. 11, Díaz gave up three hits and two runs and had to be rescued in an eventual Rockies victory over the D-backs. That rough outing began a 17-game slump in which he recorded a 10.80 ERA and a slash line against of .407/.507/.729.

“I had the confidence from Buddy, but I wasn’t ready with my mechanics,” Díaz said, with Estévez translating. “I got away with a lot of stuff, but that wasn’t the way I wanted to go through things.”

Both Estévez and Díaz are early in their spring preparation, and Estévez’s first outing was especially rough, but the health and confidence are there.

“This group of guys … we can do really good work, and get into the playoffs,” Díaz said.

“I mean, come on,” Estévez said. “We’ve got a lot of guys that can pitch in high-leverage situations right now. And not every bullpen has that."