KANSAS CITY, MO. – Twins manager Paul Molitor chooses his words very carefully when discussing his outfield defense.

"You're mostly trying to find some things out," Molitor said. "Unfortunately you have to suffer through some of the mistakes along the way as we try to evaluate where these guys are at with their careers and what they can do on defense."

That came one day after more misplays in the outfield cost the team runs. Thursday, center fielder Eddie Rosario made an ill-advised throw when he had little chance to get Lorenzo Cain at third. On top of that, he threw wildly, enabling Cain to score.

The next batter, Kendrys Morales, sent a fly ball to left that Robbie Grossman made a poor read on, which led to a gift double.

Grossman has a plus/minus rating of minus-18 as a left fielder. Plus/minus is a measure of many plays a defender makes that are above or below what an average fielder would make.

Rosario entered Friday with a minus-2 rating in left and minus-3 in center, where he is currently filling in for the demoted Byron Buxton, who is regarded as an excellent defensive center fielder.

Max Kepler was a plus-2 in right field. Miguel Sano was minus-13 before he was moved to third base.

Kepler has made solid progress defensively. Rosario racked up 16 assists last season, playing mostly in left. He has five this season. Grossman probably is the least-gifted defensively among Twins outfielders. He doesn't throw as hard as the others but tries to get off quick and accurate throws. But his routes haven't been the most direct at times, with Thursday's play being one of the worst.

"I think when you have people trying to play defense, it doesn't matter if you are in your 130th game or your 10th game," Molitor said. "There's going to be some physical mistakes. We have had more than our fair share."

Hall of Fame visit

Kennys Vargas, Michael Tonkin and Ryan O'Rourke were among the Twins players who, along with broadcaster and Hall of Fame pitcher Bert Blyleven, wandered out to the Kauffman Stadium parking lot Friday to check out the Hall of Fame Tour stopping through selected cities. Among the artifacts on the tour is the cap that Jackie Robinson wore in the 1955 World Series and the ball Babe Ruth hit for his 714th home run.

Fans also can have their pictures taken then placed on a mock Hall of Fame plaque.

Vargas really enjoyed learning about the history of the game.

"I was looking at the old uniforms," Vargas said. "They were so heavy. I don't know if I could have worn them."

The tour will be on display at the Mall of America Sept. 16-29.

Minor league trade

The Twins traded lefthanded Class AAA Rochester reliever Sean Burnett to Washington for a player to be named later or cash.

Burnett, 33, has pitched in 370 major league games, but most recently three games for the Angels in 2014.

He pitched for the Nationals in spring training but was released April 3 and briefly hooked on with the Dodgers and Braves organizations before joining the Twins as a minor league free agent May 23. He posted a 2.15 ERA in 29 games with Rochester.

Burnett was under consideration to be called up last week when the Twins were looking for emergency arms when they had to play a doubleheader Aug. 11.

Burnett also had an out clause in his contract that was approaching.

Rochester deal official

The Twins and Rochester Red Wings officially announced a two-year extension of their contract, extending an agreement that has made the Red Wings the Twins' top minor league affiliate since 2003.