Novak Djokovic says he has "high expectations" as he chases an elusive Olympic gold medal, with his confidence unshaken despite a poor year by his stellar standards.

The 24-time Grand Slam champion has not won a single title this season, losing in straight sets to Carlos Alcaraz in the Wimbledon final earlier this month.

He returns to Roland Garros for a fifth Olympics, attempting to improve on the bronze he earned on his debut at the 2008 Beijing Games.

The Serbian world number two faces a mouthwatering clash with Rafael Nadal if both players win their opening matches.

Djokovic has missed out on the podium at the past three Olympics, twice finishing fourth, including in Tokyo three years ago when his bid for a rare golden calendar Grand Slam came up short.

Carlos Alcaraz is the favourite for the title in Paris after landing his first French Open title and defending his Wimbledon crown, but Djokovic has made a habit of proving doubters wrong.

"When it comes to bookmakers, people will always talk," Djokovic said at a Serbian team press conference on Thursday.

"I haven't yet won a title in this calendar year so people tend to count me out, but it has happened before and it can always change. So it can be a motivator."

The 37-year-old pulled out before his French Open quarter-final with a knee injury at the start of June but made a swift return following an operation in time to play at Wimbledon.

"I feel more ready now than I was for Wimbledon," said Djokovic, who begins his Olympic campaign against Australia's Matthew Ebden.

Djokovic has made no secret of the fact that winning Olympic gold remains one of his "biggest dreams", as the only major honour missing from his list.

"The expectations are always high, which is something that I cannot change and don't want to," he said.

"Approaching Olympic Games is always a huge challenge for me because I put extra expectations and pressure on myself, and of course, the nation as well."

"The objective is always the highest one," he added. "I'm hoping I can perform by best and get to the medal match."

The tournament will officially mark the end of Andy Murray's career, with Nadal also nearing retirement, but Djokovic said he had no plans to hang up his racquet.

"I don't have retirement close in my mind, to be honest even though I know a lot of people would love me to retire so this era is done," he said.

A match between Djokovic and Nadal would be the 60th instalment of one the sport's greatest rivalries.

Djokovic holds a 30-29 edge over the Spaniard, but the pair have not faced off since Nadal won their French Open quarter-final two years ago.

"I am excited for this duel in the second round, and I will give it my all," he said.