US Open champion Bianca Andreescu has withdrawn from the Australian Open due to a knee injury she sustained at the end of last season. “It was a very tough decision to make as I love to play in Melbourne but I have to respect the recuperation plan for my knee and body,” the 19-year-old Canadian tweeted. “My rehab is going well, I feel better and stronger every day but after discussing it with my team and following the recommendation of the doctors, the Australian Open is unfortunately too soon in my rehab process.” Andreescu, the world number six, injure her knee at the season-ending WTA Finals in Shenzhen, China, ending an amazing year for her.