ARLINGTON, Texas — Kansas City Royals reliever Luke Hochevar has been placed on the 15-day disabled list because of swelling and numbness in his hand when trying to pitch.

The Royals made the move before Thursday night's game at Texas. The team said the right-hander has symptoms of thoracic outlet syndrome, a condition when blood vessels or nerves between the collarbone and first rib become compressed, and can cause pain in the shoulder and neck and numbness in fingers.

Manager Ned Yost said the team was still doing tests to find out exactly what is going on with Hochevar. Yost said an ultrasound was conducted earlier this week in Kansas City.

"It's like (his hand) is falling asleep," Yost said. "He loses feeling in his fingers, and we gave it a couple of days to see if it would get better."

Yost said Hochevar tried to throw a side session earlier Thursday, and that the pitcher's hand started swelling with the same symptoms about halfway through the session.

Right-hander Brooks Pounders was recalled from Triple-A Omaha. He made his major league debut pitching in three games for the Royals earlier this month, and is 5-1 with a 2.82 in 22 appearances (seven starts) for Omaha this season.

The DL move was retroactive to Monday, the day after Hochevar took the loss in a 2-1 home defeat to the Rangers. He gave up a tiebreaking homer to the first batter he faced, Delino DeShields leading off the seventh.

Hochevar is 2-3 with a 3.86 ERA in 40 appearances this season.

After missing all of 2014 because of Tommy John surgery, Hochevar was 1-1 with a 3.73 ERA in 49 appearances for the Royals last season and then went 2-0 without allowing a run over 10 2-3 scoreless innings in nine playoff appearances as the Royals won the World Series.