CHICAGO - Twins lefthander Glen Perkins said he thinks he's thrown harder as the season has progressed. The stats suggest he's throwing harder than he ever has.

He struck out Chicago's Adam Dunn on Thursday with a fastball that was clocked at 97 miles per hour by the radar gun at U.S. Cellular Field.

Brooksbaseball.net uses PitchFX technology, which is supposed to accurately measure pitch speed. The site reported that Perkins' four-seam (straight) fastball hit 97.2 miles per hour and his two-seam (sinking) fastball hit 95.8. Perkins said that's the hardest he's ever thrown a baseball.

"It's kind of where I was at before I got hurt," Perkins said. "Where I could throw it and have an idea where it was going."

Perkins landed on the disabled list twice in 2009. He said this spring training was the first in while he reported healthy and not coming off an injury. As a reliever, he can let it loose more than he can as a starter, and the radar gun readings speak for themselves.

"The last few appearances," he said, "I feel like I've gotten better."

Span update Outfielder Denard Span, working his way back from a concussion, ran the bases Friday for the first time in a month.

Span could be close to taking his recovery to Fort Myers, Fla., where he can play in games.

"He's pretty much up to speed," Twins head trainer Rick McWane said. "We're going to keep him up here through the weekend, have him repeat what he did [Friday], then see where he is after the break."

McWane said if Span gets through the weekend without any symptoms returning, he should be close to leaving for Fort Myers. Span will have to have another ImPACT test before he's cleared to play in rehabilitation games.

Other injury updates • Outfielder Delmon Young, who is recovering from a sore right ankle, was 0-for-4 Friday at Class AAA Rochester. He should be ready to be activated from the 15-day disabled list right after the All-Star break.

• Righthander Kevin Slowey, who is building up his endurance after recovering from an abdominal strain, is scheduled to start Sunday for Class AAA Rochester.

Looking ahead The Twins have yet to announce their pitching rotation after the All-Star break, but indications are that lefthander Francisco Liriano will get the ball Thursday against the Royals.

Righthander Nick Blackburn could start Friday.

Righthander Scott Baker is expected to be moved to the back of the rotation after leaving a start Tuesday because of an elbow strain. Including the All-Star break, Baker will end up with 12 days off between starts.