(CBS) The bullpen was one of the White Sox’s biggest weaknesses in 2014, and with the winter meetings upon us, they’ve set their eyes upon landing an important piece.

Chicago is showing “serious interest” in free agent closer David Robertson, according to the New York Post. Robertson had 39 saves and a 3.08 ERA for the Yankees last season.

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Robertson is reportedly looking for a four-year deal worth around $50 million, and there are a couple factors to consider before a deal could come to pass.

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The White Sox didn’t offer fellow reliever Andrew Miller a four-year deal before he signed with the Yankees recently, so to do so for Robertson would be a step up. Also, the White Sox would have to surrender a draft pick to sign Robertson after he rejected the Yankees’ qualifying offer — though it wouldn’t have to be a first-round pick, the Post reported.

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There are plenty of other relievers for the White Sox to consider as well, such as Luke Gregerson, Sergio Romo, Francisco Rodriguez, Pat Neshek, Rafael Soriano and Joba Chamberlain.