MINNEAPOLIS -- The Twins continue to be impressed by fourth outfielder Darin Mastroianni, who has been especially adept at stealing bases this season.

Mastroianni, who is hitting .262 with a .347 on-base percentage, has 11 stolen bases in 40 games, including 21 starts.

"I just like it when he takes first and then he can take second and third," manager Ron Gardenhire said. "First, you have to get on. He's very aggressive and confident. He studies the pitchers and gets really into it. And he's not afraid to talk about it."

Mastroianni, who didn't start on Sunday with Ben Revere back in right field, was at it again on Tuesday, when he stole second and third on back-to-back pitches against former Twins left-hander Francisco Liriano.

"I knew as soon as I got on, I was going to steal second and third," Mastroianni said. "I've seen Frankie pitch enough. I knew if I got on, I could run on him. We all knew that. When you play with a guy enough, you notice these things."

Sinker keys Blackburn's bounceback start

MINNEAPOLIS -- Twins manager Ron Gardenhire had some advice for catcher Ryan Doumit before Tuesday's game against the White Sox.

Gardenhire told the backstop to keep calling for right-hander Nick Blackburn's sinker, and it ended up paying off, as Blackburn turned in his best outing of the year.

Blackburn, who entered with a 7.99 ERA and had given up eight runs against Chicago in his previous start, ended up allowing just two runs over eight strong innings.

"In Chicago, I think he got away from his power sinker and so yesterday before the game, I told Doumit to tell him to just pound the sinker," Gardenhire said. "Just pound that sinker and go with it. He's pretty good at that. In Chicago, he kept spinning balls up in the zone."

Gardenhire said he's hoping Blackburn can build off that outing and can continue to trust his sinker. He threw his sinker 88 times in 106 pitches.

"That's his strength," Gardenhire said. "If he can keep doing that and we can catch the ball, we'll be OK."

Gardenhire looking to work Butera into catching mix

MINNEAPOLIS -- Twins manager Ron Gardenhire said he's going to try to find playing time for catcher Drew Butera now that Francisco Liriano is no longer with the Twins.

Butera served as Liriano's personal catcher over Liriano's last 11 starts with Minnesota, but now isn't tied to any of the club's five starters.

But Gardenhire said he's looking to give Joe Mauer a rest at some point on the club's seven-game road trip to Boston and Cleveland to give Butera a chance to start.

"I don't have to line him up with anybody," Gardenhire said. "We'll get him in a game pretty quick. He needs to catch. It'll give me a chance to mix Drew in. I know fans like to see Joe Mauer play every day, but there will be a time on this road trip where I'm going to give Joe a day off."