See more of the story

CHICAGO – The Twins weren't sure whether Phil Hughes' knee injury would end his season. There's no doubt that his shoulder surgery will.

Hughes will have part of a rib just under his shoulder blade removed on July 6, an operation to relieve pressure on the nerves and blood vessels underneath in a condition called thoracic outlet syndrome. Doctors aren't certain that the condition was responsible for the shoulder weakness and pain that Hughes experienced this season, but "it explains maybe a little bit of his issue," General Manager Terry Ryan said. "If that is the case, that's a relief."

It means, however, than any hope Hughes had of returning in September from the compaction fracture in his left knee is now gone. Hughes is off crutches and his knee, injured when he was hit by a line drive on June 9, is feeling better. But shoulder surgery will require several more months of recovery. "He'll have to rehab both injuries now," Ryan said, "and he'll be OK to go full-bore in spring training."

The condition was discovered as doctors continued to search for the cause of Hughes' shoulder condition, a search that was delayed by the knee injury. Hughes hadn't felt right all season, he said, and a 1-7 record and 5.95 ERA reflect that.

Thoracic outlet syndrome isn't exactly unheard of in baseball; former Twins prospect Deolis Guerra needed similar surgery in 2013 after blood clots were discovered as he readied for the World Baseball Classic. Cardinals pitcher Chris Carpenter and Dodgers pitcher Josh Beckett also underwent the surgery.

Prospect on U.S. team

Jose Berrios won't be making his third consecutive start for the World team at the Futures Game, but it's possible another Twins signee could get the honor. Chih-Wei Hu, a Taiwanese righthander who was shipped to Tampa Bay last July in a trade for reliever Kevin Jepsen, was one of 10 international pitchers selected to the World Team, MLB announced on Tuesday.

J.T. Chargois, the Class AAA righthanded reliever who spent a brief three-day stint with the Twins earlier this month, was the only Minnesota prospect named to either team. He will be in the U.S. team's bullpen at the July 10 game at Petco Park in San Diego. Chargois has struck out 26 batters in 20⅓ innings this season at Rochester, allowing two runs for an 0.89 ERA.

Hu is a 22-year-old righthander who posted a 2.34 ERA in 13 starts at Class AA Montgomery this season, before being promoted to Class AAA Durham, where he has made only one start.

Sano still rusty

Miguel Sano homered for the second straight game Tuesday but also struck out twice in a 1-for-4 night for Class AAA Rochester. He's now 3-for-19 in his rehab stint as he returns from a hamstring injury, with two homers and six strikeouts. "We're watching. Overall, his reports are that he still [has] a ways to go. The combination of [pitch] recognition and rustiness still need to be addressed to some degree," Molitor said. "We're open-minded about when he could return, but probably leaning to get him a few more at-bats in addition to tonight."

Trevor May faced the final three batters of the game and retired them all, two on strikeouts, to earn a save in his second rehab appearance.