MLB Trade Grades: Potential World Series preview gets more interesting with shocking swap

When the trade deadline arrives, the most common trades we see involve a team trying to make the postseason and a team that has given up on its chances to compete. The trades usually see prospects go from the contender to the selling team, while the selling team gives the contender a player who can help them win right now.

While that's the norm, there are always exceptions. We just saw one take place on Friday with a swap featuring potential favorites to win their respective leagues, the Philadelphia Phillies and the Baltimore Orioles.

Matt Gelb of The Athletic was first to break the shocking news.

MLB Trade Grades: World Series contenders fill needs with shocking swap

Here's the full trade:

While it's rare to see deals like this go down, you can't argue that this one in particular doesn't make sense for both sides. Both teams clearly benefit here.

The Phillies have had a need for a right-handed hitting outfielder all year. Brandon Marsh doesn't do much against left-handed pitching, and players like Johan Rojas and Cristian Pache haven't hit at all. Acquiring Hays, a player who has an .894 OPS against left-handed pitching this season and a .791 OPS against them in his career, makes a lot of sense as a fit.

He's not a big name like Luis Robert Jr. or Brent Rooker, but the Phillies also didn't give up any prospects in this deal, opening the door to them potentially adding more before the deadline.

The Orioles simply didn't have much of a need for Hays anymore. They're stacked on the position player side not only at the MLB level, but in the minors as well. They do, however, need pitching, and Dominguez can fit nicely in their bullpen.

The right-hander has had a bit of a down year, posting a 4.75 ERA in 38 appearances, but he has a strong track record and has a sparkling 1.13 ERA in 16 career postseason innings.

As for Pache, he doesn't offer much offensively, but he performed well against southpaws last season and is an elite defender capable of playing all three outfield positions. The deal is revolved more around Dominguez, but there's a chance Pache draws some starts against lefties.

While it's a bit disappointing that the Phillies didn't aim higher with their right-handed hitting outfield need, Hays does make them better, and Dominguez had been phased out high-leverage spots in their bullpen anyway. Hays wasn't playing much in Baltimore, and should thrive in Philadelphia, while the Orioles fill a need of their own.

While both of these players come with an extra year of club control, Hays will be entering arbitration while Dominguez has an $8 million club option that Baltimore will likely pass on. For that reason alone, the Phillies might be the winners as of now, by the slightest of margins.

Phillies trade grade: B
Orioles trade grade: B-