(CNN) Tennis great Serena Williams has been named GQ's Woman of the Year -- but the magazine's cover has caused a stir on social media with many questioning why "Woman" was in quotes.

The 37-year-old, called "The Champion" by the magazine, features in one of four covers of December's 'Men of the Year' issue wearing a black long-sleeve turtleneck leotard.

GQ, which first made women part of its Men of the Year honorees in 2003, included the American alongside actors Michael B Jordan, Henry Golding and Jonah Hill.

Williams features in one of four covers in the December issue of GQ

In February, Williams told CNN she almost died giving birth to her daughter last year, yet within months she was back training and returned to the sport earlier this year, reaching both the Wimbledon and US Open finals.

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