One of the Washington Nationals' biggest priorities this offseason was to strengthen their bullpen.

It seems as though they've been doing just that.

After signing Oliver Perez before the Winter Meetings, the Nats traded infielder Yunel Escobar to the Los Angeles Angels for hard-throwing righty Trevor Gott and added veteran righty Yusmeiro Petit.

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On Thursday, the rebuild continued as it was reported they have come to a deal with righty Shawn Kelley on a three-year deal:

The deal took a while to transpire -- it was first reported on Dec. 8 but wasn't finalized until recently.

shawn kelley will indeed wind up with the nationals, sources say

— Jon Heyman (@JonHeymanCBS) December 9, 2015

Shawn Kelley signing saga is complete. Agrees to 3-year deal with #nationals. Total payout in the $15-16M neighborhood.

— Jerry Crasnick (@jcrasnick) December 10, 2015

Kelley is a seven-year MLB veteran, but enjoyed what was easily his best season in 2015 with the San Diego Padres. The 31-year-old pitched to a 2.45 ERA with 63 strikeouts in 51 1/3 innings.

The Nationals will be Kelley's fourth team he's pitched for; he made his debut in Seattle in 2009 and was traded to the Yankees in 2013. Last offseason, the Padres acquired in him a trade for prospect Johnny Barbato.