Twins ponder how they got damaged goods in Sam Dyson

Righthander Sam Dyson on Sunday left for Los Angeles, where he will meet with specialist Dr. Neal El-Attrache on Monday about his aching shoulder. Indications are that he will need surgery.

Meanwhile, the Twins are aching for answers as to how they dealt for a reliever with a solid track record — and who apparently was injured when they acquired him.

According to sources with knowledge of the situation, the Twins have investigated whether San Francisco was aware that Dyson had a sore shoulder when the Giants sent him to the Twins in exchange for three minor leaguers, pitchers Prelander Berroa and Kei-Wei Teng and outfielder Jaylin Davis.

As standard procedure before trades are finalized, Dyson's medical information was examined by the Twins. There were no red flags on the records they examined.

Dyson, however, informed the Twins shortly after joining them on July 31 that he has been pitching with some discomfort, dating to a July 15-17 series against Colorado. He said he's had aches before and had pitched through them.

"It's something pitchers always have," he said in August. "I think everyone is always working through something … Just been grinding on it."

Dyson landed on the injured list on Aug. 3 and returned to action Aug. 13. Over the next 10 appearances, he posted a 2.53 ERA. Then he experienced more discomfort and was shut down.

The situation led to discussions between the Twins and Giants to determine what they knew about Dyson's condition before the deal was made. The Twins have been unable to find any evidence that the Giants had knowledge of an injury.

So Dyson and the Twins are bracing for surgery — and the possibility that Dyson, who's arbitration-eligible for next season, won't return to the mound until the middle of the 2020 season.

Catcher Mitch Garver left Sunday's game because of a sore hip after striking out in the fifth inning. He and the Twins believe it's nothing serious. Garver feels it's partially a result of being the lineup more often.

"This last week has been heavier than normal," he said. "If I'm not starting, I'm coming in the game at some point. It's just been a heavier workload than normal, and that's all fine. I could have stayed and finished the game, but we're looking towards one week from now, not necessarily right now."

Jason Castro replaced Garver behind the plate.

Twins manager Rocco Baldelli said outfielder Max Kepler, slowed by a strain near his left shoulder, will increase his batting practice work over the next couple of days. He also will get swings against the high-velocity pitching machine, which can be viewed as a step in the right direction.

Ehire Adrianza, out with an oblique muscle strain, hit off a tee Sunday and is scheduled to take batting practice Tuesday in Detroit.

Lefthander Martin Perez was knocked out of Sunday's game in the third inning and was charged with five earned runs.

His last two outings have been poor, giving up 18 hits over seven innings. Over his past five starts, Perez has a 9.15 ERA — and that includes a Sept. 5 outing in Boston in which he gave up one earned run over six innings. But he feels he's not pitching as poorly as his line suggests. He said Kansas City didn't hit many pitches hard.

"Sometimes you try to do your best and you don't get the result that you want," Perez said. "It's just baseball, and, mentally I'm strong. I know I'm going to face those guys again next week and I'm going to do my job."