"I couldn't refuse the chance to play with him," the world number two said Sunday of his world number one partner.
"It will be an honour to play with Rafa. I'm happy, and it's even a part of the history of tennis, that makes it even greater."
Not since Jimmy Connors was ranked first and Arthur Ashe was second when they played together 34 years ago have the top two singles players joined forces in doubles, the ATP said.
"Part of it is the fact that Davis Cup is a bit on my mind. I need to play as much doubles as possible," Djokovic said.
Djokovic, who opens in singles after a bye with either a qualifier or Julien Benneteau of France, said that with Serbia into the Davis Cup semi-finals with a September 17-19 tie at home against the Czech Republic, his hopes are high for going all the way in the team competition.
"I'm pleased that we are having Davis Cup success this year. It is one of my goals for 2010 - to try and get to the Davis Cup final," Djokovic said.
Djokovic added that after beating neighboring Balkan rival Croatia 4-1 in last month's quarter-finals, he took two weeks or much-needed rest.
"I wish it was more but I'm back and recharged and recovered," he said. "I'm ready to compete again. I have lots of expectations for myself, I want to go as far as a I can - and hardcourt is my favourite surface."