HOUSTON – Even after five months, the Twins still are learning about righthander Mike Pelfrey and the process of coming back from elbow reconstruction surgery. And what they've seen lately has been a pleasant surprise.

"I didn't know he could throw 95 [miles per hour]," manager Ron Gardenhire said. "I thought he'd settle in at 91, 92. I didn't know he could get to 95."

Pelfrey has flashed increasing speed as he gets farther away from the Tommy John procedure he underwent on May 1, 2012. Two pitches were recorded at 96 mph in his Saturday start against Texas, according to mlb.com, and he hit 95 mph several times.

But if the Twins are impressed, Pelfrey really isn't, not yet.

"I've thrown harder," the 29-year-old righthander said. "Last year, my last outing in spring training I touched 97. And my last outing before I got hurt, I was hitting 95 in the eighth inning. My velocity's getting there. I think the biggest question for me now is, how come some days I feel good, my arm feels live, and sometimes it just feels dead. That didn't happen before."

It's a natural progression after surgery, however, and Pelfrey has been told the "dead" periods should become less frequent.

"I lot of people tell me, Year 2 after surgery is when you're really back," Pelfrey said, a fact his agent, Scott Boras, is sure to emphasize when Pelfrey becomes a free agent in November.

Gardenhire said he has enjoyed the transformation of Pelfrey from a take-it-slow, run-up-pitch-counts starter earlier this year to a more classic power pitcher of late. Pelfrey posted a 3.60 ERA in six August starts, and he's given up only two runs in his past 12 innings, while striking out 10.

"He's got great stuff now. He can punch people out, blow it by them," Gardenhire said. "But quick outs is a way to stay in games longer, and he's been trying."

Keeping bullpen fresh

With another 7â…“ innings required Monday, the Twins have piled up 471â…“ innings of work from the bullpen this season entering Tuesday, only two innings less than Toronto's major-league-leading total. Yet the heavy workload hasn't burned out the relief corps; Minnesota's bullpen ERA of 3.11 ranks fifth in the majors.

"From early in the season, our biggest worry was blowing up our bullpen, burning them out," Gardenhire said, a concern that grew more serious as the starting rotation had difficulty getting to the late innings. "Our goal is not to try to hurt them. If a guy's gone a couple of days in a row, we just say, 'You're not pitching tonight.' "

Etc.

• Joe Mauer took live batting practice at Target Field on Tuesday, and continued to report no return of his concussion symptoms, General Manager Terry Ryan said. How likely is a Friday return to the lineup? "I don't know if we'll know that until we get back," Ryan said. "We'll have him examined again," likely on Thursday's off day.

• Righthander J.T. Chargois, the Twins' second-round pick in 2012 who missed the entire season because of a sore elbow, will undergo reconstruction surgery in two weeks, Twins minor league director Brad Steil said. Chargois, a relief pitcher out of Rice, saved five games and posted a 1.69 ERA for Elizabethton after being drafted last year, but was shut down after experiencing elbow pain this spring. Months of rest had him back to throwing live batting practice last month, but he reinjured the arm and will require Tommy John surgery.

• Oswaldo Arcia returned to the Twins lineup Tuesday, his wrist healed after missing all but one of the past 13 games.