The Washington Nationals have acquired their second relief pitcher in less than a half hour, dealing for Seattle Mariners left-hander Roenis Elias.

This news comes shortly after general manager Mike Rizzo reached an agreement with the Toronto Blue Jays to bring reliever Daniel Hudson to Washington, D.C.

In his second full big-league season, Elias has posted a 4.40 ERA in 47.0 innings of work with the Mariners. He is running a respectable 8.6 K/9, though his 34 percent ground ball rate leaves something to be desired.

The Nationals certainly have more left-handed depth. Tony Sipp has a 4.71 ERA, but he could see more improvement for the rest of the second half given that his FIP is a 3.56, albeit in relatively limited action. Matt Grace has struggled, but he could benefit from a lower usage rate with Elias joining the bullpen.

In fact, Elias actually has better peripherals than Daniel Hudson, with a superior xFIP and walk rate. Washington will have to hope that he can keep the ball in the yard, as he is moving from a ballpark in Seattle that was more pitcher-friendly to Nationals park, which has been slightly more hitter-friendly (with higher homer rates), according to ESPN's Park Factor.

With the Nationals making moves around the edges, the bullpen market continues to narrow even further. They are likely out of the running for Detroit Tigers closer Shane Greene, and may also be out on Chicago White Sox reliever Alex Colome.

Regardless, general manager Mike Rizzo was aggressive in pursuing relief depth to try to put this Nationals team over the top in the playoff race.