DENVER -- Rarely do media visiting the Rockies clubhouse bother left-handed reliever Mike Dunn when the mood is good.

A couple days ago, he was happy, not only with his Sudoku puzzle but with job-related paperwork. The Rockies activated him from the 10-day injured list, with his left A/C joint declared recovered from inflammation and the popping of scar tissue from last fall’s surgery.

But he understands that as a lefty reliever who often faces dangerous hitters, sometimes he’ll fall short and reporters will need a story. Of course, he had no idea the story would come Friday night with his rough return to action -- four runs on four hits, including one of Hunter Renfroe’s three home runs, while recording one out in an historically poor ninth inning of an eventual 16-12, 12-inning loss to the Padres at Coors Field.

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A day earlier when there was no story, Dunn looked up from his puzzle and told how he learned to deal with being the story.

“I had good mentors coming up who said that if you affect the game, make sure you’re available to answer to it,” Dunn said. “I came up with the Yankees and listened to Mariano Rivera a lot. And when I went to Atlanta, Billy Wagner was my throwing partner the second half of 2010. I got to talk to him a lot.

“He gave me a lot of insight on the mental side of the game, video work and different things. I would say he’s probably my No. 1 mentor, especially on the mental side of things. He’s left-handed, a fastball-slider guy.”

Dunn, 34, figured if two of the sport’s best could handle the heat, so could he.

“You joke around in a sense that relievers are in a sense like punters and kickers in football -- you fly under the radar unless something bad happens,” Dunn said.

Friday night’s game, little did he know, would be a kick in the teeth.

Of course, there were many shanked punts and missed field goals from the Rockies’ bullpen, which entered the game a tidy third in the National League with a 3.94 ERA. On Friday, starter Jeff Hoffman gave up one run -- the first Renfroe homer -- in five innings. That meant 15 runs in seven innings, and the bullpen ERA rose to 4.38 to plummet the rank to ninth.

Dunn and closer Wade Davis, who gave up two runs on three hits, a walk and a wild pitch while blowing a save for the first time after eight successes this season, presided over the first ninth-inning blown lead of six runs in club history. And in the 12th, righty Jairo Diaz gave up five runs, including Renfroe’s third homer, and five hits.

But Dunn’s struggles were key.

The Rockies entered the ninth leading 11-5. It was a good time to get Dunn back on the mound for the first time since June 2. Fernando Tatis Jr. opened with jam-shot single and Dunn fanned Josh Naylor.

Then it turned ugly with hits by Manny Machado, Eric Hosmer -- on a ground ball on the 10th pitch of the at-bat after Dunn jumped ahead with an 0-2 count -- and by Renfroe, who sent Dunn’s final toss of the night into the left-center stands on one of the many pitches left too high.

“When you pitch up, it’s dangerous,” Rockies manager Bud Black said.

While the bullpen has generally performed well, the experienced lefties have struggled -- with health being a factor. Chris Rusin missed much of of the early going with a back injury and eventually found himself waived and sent outright to Triple-A Albuquerque. Dunn, at the end of a three-year, $19 million contract, must get his shoulder right, and Jake McGee, in the midst of his three-year, $27 million deal, has missed time this year with a left knee injury.

Black didn’t buy the suggestion that Davis’ lack of command and control was due to the fact he wouldn’t have been pitching had Dunn succeeded, saying, “All closers, especially veteran closers, are always ready.”

As promised, Dunn was ready afterward.

“I felt good physically, just trying to do my job and get three outs,” he said, understandably not in the mood of the previous afternoon. “The team played a great game and I blew it. That home run, I was trying to go up and in, and I missed out over the plate.

“There’s no excuse.”