Diamondbacks acquire reliever A.J. Puk in trade with Marlins - ESPN

The Arizona Diamondbacks acquired left-handed reliever A.J. Puk from the Miami Marlins on Thursday night, the first major trade of a deadline season that has been slow because of a lack of teams unloading players.

Miami, one of the few teams expected to be busy subtracting from its major league roster before the July 30 trade deadline, received slugging infielder Deyvison De Los Santos and center fielder Andrew Pintar in the trade.

Puk, 29, began the season in the Marlins rotation as they tried to transition him back to a starting pitcher after two excellent years in the bullpen. He returned to a relief role in mid-May and has been one of the most effective pitchers in baseball since, posting a 2.08 ERA with 33 strikeouts in 30⅓ innings and an opponent slash line of .159/.204/.252.

Arizona, the defending National League champion, is 53-50 and one game back of the third wild-card spot. The Diamondbacks' bullpen in particular has struggled, owning the lowest strikeout rate in MLB with 7.39 per nine innings and the 22nd-lowest ERA at 4.24.

Puk joins closer Paul Sewald, right-handers Justin Martinez, Ryan Thompson, Kevin Ginkel and left-hander Joe Mantiply as Arizona's main bullpen options. The Diamondbacks' rotation should be fortified soon, too, with the expected returns of right-hander Merrill Kelly and left-hander Eduardo Rodriguez from shoulder injuries next month.

The Marlins, who are expected to move closer Tanner Scott and could also trade center fielder Jazz Chisholm, first baseman Josh Bell, left-hander Trevor Rogers and others, received an elite power bat in De Los Santos, whose exit velocities rank among the highest in the sport.

De Los Santos has spent more than half the season at Triple A despite just turning