Federer out for 'many months,' to miss US Open

Roger Federer announced on Instagram that he is going to miss the US Open and be sidelined for what he said will be "many months" because he needs a third right knee surgery.
Read more: https://www.espn.com/tennis/story/_/id/32028913/roger-federer-needs-third-knee-surgery-many-months?source=Snapzu