Khalil Mack is set to become a free agent for the first time in his 11-year career. Whether the Los Angeles Chargers linebacker decides to test the waters, though, is not the first thought on his mind.

American Alex Michelsen claimed the biggest win of his career when he stunned Stefanos Tsitsipas 7-5 6-3 2-6 6-4 in the first round of the Australian Open on Monday as the Greek 11th seed became the first major casualty at Melbourne Park.

Former Chicago Bears star pass rusher Khalil Mack, now with the Los Angeles Chargers, is contemplating his next move. For the first time in his NFL career, Mack enters the offseason as an unrestricted free agent, but according to ESPN , he's mulling retirement after a 12-year career.