Rafael Nadal’s title defence looks in jeopardy after he ruled himself out of the Roger’s cup in Toronto.
The couple, who are expecting their first child later this year, arrived on Tuesday in Montenegro.
The 27-year-old Serb first reached No. 1 after earning the 2011 Wimbledon trophy.
Mirza achieved a career-best number five rank in the world as the new WTA doubles chart was released Monday.
Federer is convinced he will continue to compete with Djokovic, Nadal and Murray for Tennis’s major prizes.
Djokovic went back to the top of the world rankings on Monday while Andy Murray slipped to number 10.
Djokovic overcomes Federer in an epic battle to claim his second Wimbledon title.
Novak Djokovic denies Roger Federer a record eighth All England Club title.
The Swiss maestro has not reached a grand slam final since clinching the Wimbledon title in 2012.
Petra Kvitova defeated Eugenie Bouchard in just 55 minutes for first Major in three years.
Kvitova produced one of her most dominant performances on grass-court to beat Bouchard 6-3, 6-0.
Djokovic saved a set point in the ninth game and three more in tiebreak before sealing the contest.
Paes-Stepanak bowed out after their 6-7, 3-6, 4-6 loss to Vasek Pospisil and Jack Sock.
Federer defeated Raonic 6-4, 6-4, 6-4 while Djokovic had to struggle to overcome Dimitrov 6-4, 3-6, 7-6, 7-6.
Eugenie Bouchard defeated French Open finalist Simona Halep Thursday to advance to the Wimbledon final.