PITTSBURGH -- Returning to the Majors for the first time since 2017 after dealing injury and family tragedy, right-handed relief pitcher Jairo Díaz joined the Rockies on Wednesday, with his arm and his strategy intact.

Diaz, who has a 0.45 ERA in 20 innings over 16 games at Triple-A Albuquerque, was called up to replace closer Wade Davis, who was placed on the 10-day injured list with a left oblique strain.

"I'd be lying if I said I wasn't waiting for that call, but I didn't expect it to be so soon," said Diaz, who turns 28 on Monday.

Diaz debuted with the Angels in 2015 and made 21 appearances with the Rockies in '15, with a 2.37 ERA. However, he missed '16 because of Tommy John surgery and made just four MLB appearances in '17. During that entire time, Diaz was dealing with a family tragedy.

His wife, Dubraska "Duby" Daiz, fought a lengthy battle with stomach cancer that eventually took her life in October 2017. Diaz did not discuss his wife’s battle publicly, and the organization gave him time off as needed -- the couple has a young daughter, Hannah -- and respected his wish not to go public.

“For him to be in this spot, back with us, is such an uplifting thing for all of us, and I am so happy for him, as are all his teammates and all the people in the organization,” Colorado manager Bud Black said.

At Albuquerque this year, Diaz pitched with the same tools that made him effective before -- a firm fastball and a hard slider. Only he has learned to use his pitches better. As a result, he has 22 strikeouts and six walks, and a .171 batting average against in Triple-A.

"Everything is the same -- I'm throwing just as hard, pitches feel the same," Diaz said. "The biggest difference is just the way I'm using them, the command. The biggest one is the slider. Using that whenever I can, whenever I want, is the biggest key."

The roster move has been in the works for more than a day. After the Rockies were off on Monday, the club went into Tuesday night’s game against the Pirates not intending to use Davis (1-1., 2.45 ERA, seven saves in 14 2/3 innings), but it did not announce an injury.

Davis felt discomfort in the oblique during his last appearance, when he earned a save in Colorado's 5-4, 11-inning victory at Boston on May 14. His condition never improved.

“He was throwing the ball great," Black said. "I thought he really threw the ball well in Boston."

Black added that righty Scott Oberg (1-0, 3.60 ERA) will be the primary closer in Davis’ absence.

To add Diaz to the 40-man roster, Colorado placed lefty Tyler Anderson on the 60-day IL with a left knee chondral defect. The Rockies announced Tuesday that Anderson would have surgery and a return this season is uncertain, but the announcement of his condition shed light on a difficult season.

After three struggling starts, Anderson went to the IL with what was termed left knee inflammation. His performance did not improve after his return, and the club optioned him to Triple-A with an 0-3 record and a 11.76 ERA in five starts.

Anderson never pitched for Albuquerque, and instead, he's been visiting doctors to seek opinions and treatment options. Neither Anderson nor the club have detailed the injury, nor publicly discussed his condition. The website of the Steadman Clinic in Vail, Colo., which has a relationship with the Rockies, says, in part, that “chondral damage is graded from mild to severe and all grades can have characteristics of osteoarthritis.”