With an All-Star set-up man and a closing pitcher who is yet to blow a save opportunity, the New York Yankees' bullpen is one of the team's primary strengths. However, the opportunity to upgrade their bullpen from formidable to nearly unstoppable would be an enticing opportunity.

According to Buster Olney of ESPN.com, the San Diego Padres, who are in the midst of a disappointing 2015 season, could end up being one of the biggest sellers at the trade deadline. Among the potential players that they might be willing to trade is All-Star closer Craig Kimbrel.

Kimbrel is still just 27-years-old and a four-time All-Star. He was traded to the Padres just prior to the beginning of the regular season along with his teammate from the Atlanta Braves, Melvin Upton, in exchange for Cameron Maybin, Carlos Quentin, Matt Wisler and Jordon Paroubeck, 

Alongside the big-time acquisitions of Justin Upton, James Shields, and others, the Padres were expected to be the class of the N.L. West. At this point, though, they sit in fourth place with record of 41-49, 10 games back of the first place Los Angeles Dodgers. Unfortunately for Kimbrel, his season mirrors that of the Padres' as a disappointment.

Despite having decent numbers, they are far from the league-leading totals he posted with the Braves. In 35 games, Kimbrel is pitching to a 3.24 ERA with 23 saves and the lowest K/9 total of his career (13.0). Previous to 2015, Kimbrel never posted an ERA over 2.10 or recorded fewer than 42 saves in a season in which he appeared in more than 21 games.

Olney lists three teams, including the Yankees, who might be interested in acquiring Kimbrel should the Padres intensify their effort in dealing him. Via YanksGoYard:

"Kimbrel makes $9 million this year, $11 million next season, and $13 million in 2017, and on paper, he’d be a great fit for the Red Sox, maybe the Jays (though he is probably too expensive) and the Yankees, who could add to a bullpen that could own October."

The Yankees are currently in first place in the A.L. East with a record of 48-40. They have been rumored to be in the market for a starting pitcher because of uncertainty and injury questions hovering over the rotation. Inconsistency from CC Sabathia and injury concerns for Michael Pineda, Ivan Nova, and Masahiro Tanaka are all motivating factors for the Yankees to acquire a starter.

However, if the Yankees elect to acquire another dominant reliever, they will be able to make every game essentially a six-inning affair with a potential three-headed monster of Kimbrel, Dellin Betances, and Andrew Miller closing out games.