"Obviously, it's a shock, and I had to work through that," he said.
Sullivan was batting .212 through June 1, and that was an improvement over where he was for much of April and May. But he got over his blues.
After going 19-for-31 with four of his nine total doubles, one of his three triples and his only home run while hitting safely in 10 straight games, the Rockies promoted Sullivan, who was in uniform for Saturday night's game against the Devil Rays.
Granted, this is a different opportunity.
With Willy Taveras having grasped the center-field and leadoff jobs -- that was the plan when the Rockies acquire Taveras from the Astros during the winter -- Sullivan is a left-handed bat off the bench, a pinch-hit option and a possible late-innings defensive replacement.
Ryan Spilborghs has earned fourth outfielder status, so Sullivan will be behind him and probably Jeff Baker, who also plays corner infield positions, in terms of getting starts. But Sullivan believes he can help.
"This team is playing well," Sullivan said. "Hopefully, I can just be an addition to that."
The Rockies summoned Sullivan because a younger prospect, Sean Barker, who was called up last week, was hardly getting on the field. The Rockies want Barker to get regular at-bats, and are trusting Sullivan will embrace backup duty.
"Sullivan's been playing extremely well as of late," Rockies manager Clint Hurdle said. "We wanted to revisit that, see what value Cory can bring. We believe he can add value.
"It's a different opportunity from what he's had in the past."
Sullivan made the Rockies as a surprise in 2005 and finished with a .294 average, but as a starter for most of last season he dipped to .267 with a .321 on-base percentage. He also had 183 strikeouts in 764 at-bats.
However, Sullivan had his moments in Spring Training while batting .333, but the addition of Taveras and the Rockies decisions to use since-released veteran Steve Finley as the backup in center pushed him down the depth chart.
Sullivan's numbers and big-league prospects rose when his outlook improved.
"After about a month, I jut really started to see the ball well and put good swings on it," he said. "The last month has been fun. It's just building confidence. The swing's the same. The stance is the same. I'm just starting out with a good, solid approach."
Let's talk 'D': The Rockies entered Saturday leading the National League in fielding with a .990 percentage, two percentage points higher than the Mets.
Every team talks about fundamentals, but the Rockies never stop discussing it and emphasizing it.
"We revisit things day in and day out," Hurdle said. "We don't have chalk talks, but we have defensive meetings periodically. We have monthly preparation work that our coaches do on each individual on their target points for the next month.
"There's just attention to detail every day. We have [special front office assistant Walt] Weiss around, we've got [third base coach Mike] Gallego. [Outfield instructor] Glenallen Hill has come in from the outfield standpoint and added another dimension, and Davy [Collins, the former outfield instructor] was very good.
"...It's all about pride, focus and preparation. You get more of what you focus on."
Championship example: Hurdle said he is detecting an unselfishness that is "the hardest dynamic to have happen" for a team. But at least, Hurdle noted, pro sports offer an example for clubs to follow.
"Look what the Spurs have done in San Antonio," Hurdle said. "That's one of the best dynamics in pro sports, and I think it's the least written about. All we see is complaints about how it's boring baskets, boring basketball. It's winning basketball."
Up next: Rockies right-hander Aaron Cook (4-3, 4.37 ERA) will start against Devil Rays lefty Scott Kazmir (4-3, 4.07) in the finale of the three-game set Sunday at 1:05 p.m. MT
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.