"The fact he hasn't lost a match on grass this season says it all about his quality," Djokovic is quoted as saying by Sky Sports News.
"He's definitely the man to beat here now, and winning against Andy in straight sets, many people look at him as a potential grand slam winner. So now that's maybe here, or maybe in the grand slams to follow.
"He has won tournaments on different surfaces this year, so he has the ability to adjust. He's getting more experienced now playing on the big stage, which is definitely useful for big tournaments like this."
Djokovic, 27, has now missed out on just one of the last 17 Grand Slam semi-finals.