Rafael Nadal says he does not know what his future holds after being knocked out of the Paris Olympic men's doubles with Carlos Alcaraz on Wednesday.

The Spaniards were expected to challenge for the gold medal but instead lost their quarter-final in straight sets to Team USA's Austin Krajicek and Rajeev Ram.

Nadal hinted after his second-round defeat to Novak Djokovic in the men's singles that he would make a decision on his future after the Olympics were over.

After missing out on the chance to challenge for a third Olympic gold medal, having won the singles in 2008 and the doubles in 2016, the 38-year-old made an emotional exit off the court at Roland-Garros, where he has won 14 grand slam titles.

"For me, personally, it was disappointing to not bring back a medal for Spain," Nadal told reporters. "I tried my best in every single minute I was on court, but it was not enough.

"If this was the last time, it was an unforgettable feeling and emotion. They gave me the love and support every single second, and it's super, super special to feel that.

"I don't know what's going to happen in the future, but if that's the last time, I enjoyed it."

Nadal skipped Wimbledon to ensure he would be fit for the Olympics after another injury-hit season.

The next major event is the US Open later this month, but the 22-time grand slam winner is unsure if he will be fit to compete in New York.

"I can't give you a clear answer," he added. "I need some time, but for me, it looks difficult."