The Washington Nationals have been in search of a new closer after incumbent shutdown man Mark Melancon elected to sign with the San Francisco Giants earlier this winter.

As spring training approaches, Washington is zeroing in on a potential replacement.

According to Ken Rosenthal of FoxSports.com, the Nationals have discussed a trade for closer David Robertson of the Chicago White Sox, a team in rebuilding mode.

The White Sox dealt ace Chris Sale to the Boston Red Sox in December and have already done business with Washington as well, trading outfielder Adam Eaton to the Nationals in exchange for a haul of prospects headlined by right-hander Lucas Giolito.

Robertson, who turns 32 in April, converted 37 of 44 save opportunities for Chicago last season while posting a 3.47 ERA and 75/32 K/BB ratio across 62 1/3 innings. He owns a 2.97 ERA over his nine-year career and has saved 110 games during the past three seasons since becoming a full-time closer.

The right-hander is owed $12 million in 2017 and $13 million in 2018. Rosenthal writes that Washington "does not want to absorb Robertson's entire obligation, and does not want to move additional prospects after parting with three young pitchers for Eaton, sources say."

Current ninth-inning options for the Nationals include Shawn Kelley and Blake Treinen.

-- Nick Ostiller