Rafael Nadal says he does not know when he will play again after losing in the US Open fourth round.
"I need to go back. I need to fix things, life, then I don't know when I'm going to come back," said the 22-time Grand Slam champion.
"I'm going to try to be ready mentally. When I feel that I will be ready to compete again, I will be there."
Nadal is scheduled to be playing in the Laver Cup, alongside Roger Federer, Novak Djokovic and Andy Murray, in London from 23-25 September.
The loss to 22nd seed Tiafoe was Nadal's first defeat in a Grand Slam this year.