Taylor Fritz believes it is "unrealistic" to expect tennis to return to normality before the US Open in August.
The coronavirus outbreak has played havoc with the tennis season, causing the cancellation of Wimbledon and pushing the French Open back until September.
Tournament organisers are hopeful that the US Open, scheduled to begin in New York on August 25, can go ahead but world No 24 Fritz isn't so sure.
"They are aiming for a certain time, but I think that time is a little bit unrealistic," Fritz said. "The goal is to play the US Open but personally I don't know how they are going to be able to do that.
"They want to be optimistic but it is tough as it keeps being pushed back."
With both the ATP and WTA tours suspended until mid-July at the earliest due to the coronavirus pandemic, Fritz is making the best of isolation at his house in Los Angeles.
Fritz, who reached his first ATP Final before losing to Rafael Nadal at the Mexican Open, has a gym set up at home and use of a private tennis court.
He believes his extra work during isolation could pay dividends when play resumes.
"I am spending more time working out than in training these days. There is nothing else I can really do," the 22-year-old said. "I could [play] right now. I have been practising enough to keep my level and then with all the gym stuff I have been doing I am in the best shape ever.
"I am ready to go. I think this time is going to be really interesting when all the players come back to play because then you are going to see which players took the time to work on their fitness and get stronger and what players didn't work during this time."
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