Diamondbacks trade raises bar for contenders in NL wild-card race

Per FanGraphs, the Diamondbacks entered Thursday ranked 22nd in reliever earned run average (4.24) and last in reliever strikeouts per nine innings (7.39).

Puk should instantly improve the relief staff. As ESPN's Jeff Passan noted, since returning to the bullpen midseason, the six-year MLB veteran has a 2.08 ERA with 33 strikeouts in 30.1 innings.

Arizona, the winner of last year's NL pennant, is one of six teams within three games of each other in a bonkers wild-card race. The Braves (54-46), Mets (53-48) and Padres (55-50) currently hold the three playoff spots.

The Cardinals (53-49), Diamondbacks (53-50) and Pirates (52-50) are breathing down their necks, and Arizona made the first bold move to claim one of the wild-card berths.

The other top contenders in the race might have more urgency to add to their rosters following the Puk trade.

As MLB.com notes, the Braves and Pirates need outfield help. Per Baseball Reference, the Braves are 28th in outfielder wins above replacement (-2.5) and the Pirates are 24th (-2.2). 

The Cardinals and Padres must improve their starting pitching, while the Mets, like the Diamondbacks, have relief pitching as their top need.

There might be a flurry of deals before the trade deadline as teams look to separate themselves from the rest of the field. 

Puk should be the first of many dominoes to fall.