Robertson had arthroscopic surgery on his left knee to clean up his meniscus, Scott Merkin of MLB.com reports.

EDGE Analysis

Robertson apparently was pitching through the ailment for a while, although it didn't seem to inhibit him much during the season as he posted 37 saves. The White Sox are confident that the right-hander will be able to pitch without restriction when spring training rolls around, so this procedure likely will not affect his outlook for the upcoming season.