Rafa Nadal refused to make excuses for his shock defeat by Diego Schwartzman in the quarter-finals of the Italian Open, insisting that his focus is now on fine-tuning his game ahead of the French Open which begins September 27.

The nine-time Rome champion looked well off the pace in his 6-2 7-5 loss to the 15th-ranked Argentine, an opponent he had defeated nine straight times heading into Saturday's encounter in the Italian capital.

"We can find excuses, but I didn't play well enough. Then we have to think internally, 'Why? How I can fix it?'" the 34-year-old Spaniard told reporters. "Now is not the moment to find excuses. It's just to accept that I didn't play well enough."

"It was not my night. He played a great match, I think, and I didn't. These things can happen. After such a long time without competing, I played two good matches, and now I played a bad one against a good opponent.

"That's how it is. I just want to congratulate Diego and I'm going to keep working."

Nadal, who skipped the U.S. Open in New York due to COVID-19 concerns, said he would regroup before heading to Paris, where he will bid for a record-extending 13th title.

"It's a completely special and unpredictable year. I probably will go back home and then let's see what's going on," the 19-time Grand Slam champion said.

"I did my job here. I did a couple things well and other things bad. I'm going to keep working and keep practising with the right attitude and try to give myself a chance to be ready."