Cabrera said Tulsa manager Duane Espy surprised him Monday night with the news that he was headed to Denver.
"Espy said, 'I want to tell you something; you're going somewhere,'" Cabrera said. "He didn't tell me where. Ten minutes later he told me, 'Congratulations, you're going to the big leagues.'"
Tracy also announced that lefty Josh Outman -- who threw 96 pitches Saturday night and is working in a four-man rotation -- had his next start moved from Wednesday to Thursday. Tracy is intrigued by Cabrera.
"Just take a look at what he's done so far," Tracy said. "He's a strike-thrower. This is another young kid that's going to pitch in the big leagues for the first time. You've got to give him an opportunity not only to get his feet wet, but get a chance to settle in at this level and see what it's all about.
"He's coming from Tulsa, and I believe at this time last year he was an Asheville Tourist. That's a lot of progress in a very short period of time, but this is a much different league than the South Atlantic League or the Texas League. We'll give him an opportunity to see how he handles it."
Cabrera, 24, has baffled Minor League hitters with a four-seam circle changeup that he can throw into the strike zone or have dive out of the zone in the hitting area. He can make the pitch have screwball action.
Cabrera also throws a two-seam fastball. At the request of Tracy and the Major League staff after Spring Training, he has been developing a breaking pitch that he says is improving rapidly.
Cabrera, whose big drawback is the home run (15), is not concerned about facing Major League hitters.
"For me, it's the same game, here, Double-A, Single-A, everywhere," Cabrera said.
The Rockies optioned right-handed reliever Zach Putnam to Triple-A Colorado Springs. Putnam has made two scoreless appearances, one during the Rockies' 12-5 loss to the Nationals on Tuesday night, in three call-ups to Colorado.