"I said 'How do you feel?"' said the 38-year-old DeRosa. "He said 'I feel great.' And I said 'That's how it should be. You should be able to walk away on your own terms.'
"So I'm happy for him."
Oliver retired on a high note Sunday, striking out two Tampa Bay Rays in the swansong to his 20-year major-league career.
The 42-year-old left-hander came on to a standing ovation to open the seventh against the meat of the Rays order, with Toronto trailing 7-3. He struck out Wil Myers and Evan Longoria while inducing James Loney to fly out.
He threw 11 pitches, eight for strikes, before giving way to Steve Delabar for the eighth inning in a game Toronto lost 7-6 after a comeback fell just short in the final game of the Jays' season.
"It was great, a great run," Oliver said of his career. "But eventually every good thing must come to an end, unfortunately. Mine just happened to end at 42, I guess. But that's all right. It was great."
The six-foot-three 250-pounder leaves the game with a 118-98 record in 766 games and 1,915.2 innings pitched. He struck out 1,259 and walked 720 in a career that included three stints in Texas as well as stops in St. Louis, Boston, Colorado, the Angeles and Mets.
"He had some kind of career," said Jays manager John Gibbons. "Twenty years -- very few guys get to do that.
"To play a very, very small part and be able to manage him is a pretty neat thing. He was one of the better pitchers in the game for a long time. Longevity in this business is hard to come by but to do it for that long and be that effective until the very end, that speaks volumes."
Added DeRosa: "I look more at not only what he's been able to accomplish but the way he's gone about it. With class and grace. He's handled himself like a pro from start to finish."
Oliver, the son of former major league infielder Bob Oliver, returned this season after the Jays exercised a US$3-million option for 2013
During spring training, he said good health, good teams and good coaches helped keep him in the game so long. He also worked at it, studying opposition batters.
"There's really no magic explanation why I've stayed around so long," he said.