Rafael Nadal has said he will not push to play in singles at his farewell Davis Cup appearance next month unless he is “100% sure” he is ready to win his match.

Nadal, 38, announced on Oct. 10 he will retire from tennis after next month’s Davis Cup. He will be part of the Spain team seeking to win the tournament in Malaga, coming up against the Netherlands in the quarterfinal.

Nadal is playing in the Six Kings Slam in Saudi Arabia and will face Novak Djokovic on Saturday in the third-fourth match playoff after both lost their semifinals on Thursday.

Nadal’s defeat to Carlos Alcaraz on Thursday in Riyadh was his first match back on court since announcing his retirement, and he said after the defeat there were no guarantees he would feature for Spain in the singles next month unless he felt physically ready.

“Emotionally, I’m sure I’ll be ready. Physically and in terms of tennis level, there remains a month left to prepare,” Nadal said. “I will try to be in good shape to help the team to win. If I don’t feel ready for the singles, I’ll be the first one to say.

“Be 100% sure, I will not be on court if I don’t feel ready to win my match.”

Nadal could still partner with Alcaraz at the Davis Cup for the doubles tournament and said he will remain on standby if he can help the 21-year-old with any guidance after his retirement.

“He’s going to do very well with what he’s got. He’s learning all the time,” Nadal said.

“We can see he’s developing in every way. But of course I’ll be ready whenever he wants to call me.”