The intrigue began during spring training when Glen Perkins hit 95 miles per hour on the radar gun. It had to be once-in-a-lifetime moment, right?

On Friday, he fired three fastballs at San Diego's Alberto Gonzalez that hit 95, 94 and 94 on the Target Field radar gun. Gonzalez struck out swinging, looking overmatched. Perkins never had thrown that hard before. The website backs it up, listing his average fastball this season at a career-high 92.8 mph.

But pointing to the extra oomph of his fastball as the reason why Perkins is thriving as a reliever is only part of the explanation.

He comes to the park several days a week knowing he can be a factor in the game instead of waiting for his next start. He likes late-inning battles. After years of the Twins wondering if Perkins is a starter or a reliever, Perkins made the decision for them by emerging as the most trusted left-handed reliever in the bullpen.

"You feel more like a part of the team,'' he said. "You feel more like an everyday player. It suits my personality a lot better than the other way. I like coming here every day, getting ready to play in a game and not getting ready to make my next start five days from now.''

Perkins, 28, has a 1.82 ERA in 24 appearances with 10 walks and 26 strikeouts in 24 2/3 innings.

In 44 career starts, he's 18-12 with a 5.06 ERA. He still throws a starter's repertoire of a fastball, slider and changeup out of the bullpen.

Perkins always has had a deceptive delivery, eliciting swings from hitters as if the ball is getting to the plate faster than expected. Twins manager Ron Gardenhire pointed to Perkins' ability to pitch inside and use his slider as other reasons why Perkins has been effective as a reliever.

Gardenhire and pitching coach Rick Anderson still are looking for other relievers to step up in the bullpen, which has struggled at times this season. They felt Perkins' absence earlier this month when he landed on the 15-day disabled list because of a strained right oblique.

"He's kind of settled in and decided, 'This is what I want to be. I want to help this bullpen out,' '' Gardenhire said. "He has decided in his mind that this is what he wants to do.

"You have to take a role and grasp it and nurture the role that you are in. I think he's done that. He enjoys the challenge of going out every day with a chance to make a difference in a ballgame.''

It helps that Perkins is throwing a little harder. The difference between his fastball and changeup is nearly 10 mph, the type of separation that pitchers desire.

But when the radar gun hits 95, opposing hitters notice that and gear up for the fastball. Perkins feels he has a big advantage then.

"I can count on my hand how many fastballs I've thrown by guys,'' Perkins said. "The swings I have been getting have been on the slider when they know they have to get ready quick to hit a fastball.

"I threw [San Diego's] Rob Johnson four sliders and he swung and missed at three, thinking that at some point I was going to throw a fastball. It's hard to cover both sides.''

Perkins has made so much progress that he was going to be the closer Sunday if Matt Capps needed a day off.

"It's fun to be able to pitch in a game when the game is on the line,'' Perkins said. "I think that's where everyone wants to be. Whether you are starting a game and trying to go deep in a game or pitching later in the game in the bullpen.

"It's been a lot of fun, and I think it's something as I get used to it, I can get a little better.''