Fourteen-time Grand Slam champion Rafael Nadal says he has switched focus to 2017 after being beaten by world number 31 Viktor Troicki in his Shanghai opener.
The Spaniard, who missed two and half months with a wrist injury, was beaten 6-3 7-6 (7-3) by the Serb in an hour and 34 minutes on Wednesday.
"I need to create pain for my opponent. It is something that is not happening very often now," said the 30-year-old.
Nadal is now fifth in the world.
This marks the first time since that both he and Swiss Roger Federer have been outside the top four since 2003.
Both players will slip further when the rankings are updated next week, with Nadal dropping out of the top five.
|Race to the O2 - 2016 season rankings|
|1. Novak Djokovic||10,240|
|2 Andy Murray||8,685|
|3. Stan Wawrinka||4,970|
|4. Milos Raonic||4,600|
|5. Kei Nishikori||4,360|
|6. Gael Monfils||3,535|
|7. Rafael Nadal||3,290|
|8. Dominic Thiem||3,205|
"I've two and a half months to put myself at the level I need," added Nadal.
The Spaniard has been a fixture at the season finale World Tour Finals for the past 11 years, but is in danger of missing out on one of the eight places for the London showpiece.
He believes that recovering the destructive power that he had on his forehand is key to returning to the top of the game.
"I need to recover the forehand. I know I need to hit forehands," he said.
"I need to move faster to hit more forehands. But I need to be more confident with the forehand to make that happen. Everything is a cycle."
Since losing in the bronze-medal match at Rio 2016 on his return from injury, Nadal has now failed to make the semi-finals of his past four tournaments, having previously been beaten by Borna Coric in Cincinnati, Lucas Pouille at the US Open and Grigor Dimitrov at the China Open.