"If you really think about it, Roger and Rafa are still playing great tennis. And the only reason maybe the top four or five are not the top four or five right now is because Andy's hurt, Novak's coming back from injury and Wawrinka's coming back from injury. It's really opened up the door for a lot of guys to be able to say, `Hey, this might be my chance,"' Chang said.

Source: Los Angeles Times May 27, 2018 07:30 UTC