Back at the trade deadline, the Minnesota Twins acquired reliever Sam Dyson as part of a four-player deal with the San Francisco Giants. Dyson was in the midst of a fantastic season -- in 51 innings with the Giants he had posted a 2.47 ERA and 6.71 strikeout-to-walk ratio -- and was expected to help shore up the back of Minnesota's bullpen.

Unfortunately, Dyson hasn't done that. He's made 12 appearances since the deal, accumulating a 7.15 ERA and 1.33 strikeout-to-walk ratio. He won't get the chance improve those numbers, either -- at least not anytime soon. That's because Dyson is expected to miss the remainder of this season, and half of next, once he undergoes shoulder surgery.

The Twins are, predictably enough, not thrilled with the development -- to the extent that they've begun "investigating" whether the Giants knew about Dyson's bum shoulder before completing the deal. Here's more, courtesy of La Velle E. Neal III of the Star Tribune

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.

[...]

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.

At this point, there's zero reason to think the Giants will face a penalty or any kind of sanctioning for their dealings. The situation is somewhat reminiscent of what happened with the San Diego Padres and general manager A.J. Preller back in 2016. Preller, for those who don't know, was suspended 30 days after the league determined he hadn't been forthcoming about the health of left-handed pitcher Drew Pomeranz (then dealt to the Boston Red Sox), among others. Months later, the league standardized the process of recording and exchanging medical records. 

Dyson has one more year of team control remaining, as such it's possible his story with the Twins isn't yet finished. Still, this isn't what the Twins had in mind when they surrendered Jaylin Davis, Prelander Berroa, and Kai-Wei Teng in exchange for his services.