Rafael Nadal has vowed to work even harder to "change the dynamic" of his season after losing an epic semi-final to Pablo Cuevas at the Rio Open.
Former world number one Nadal was beaten 6-7 (6-8) 7-6 (7-3) 6-4 in just under two and a half hours on the Brazilian clay.
Nadal, dubbed the 'King of Clay', has now lost two tournaments in a row in the semi-finals on his favoured red surface having been beaten by Dominic Thiem at the Argentina Open last week.
The Spaniard, who suffered a shock first-round defeat to Fernando Verdasco at the Australian Open, will now go back to the drawing board ahead of next month's Masters 1000 tournament in Indian Wells.
"I lost an opportunity, that's it," Nadal said.
"I fought until the end. I have to accept it and keep working to try to change the dynamic. I have to work hard to change it.
"I didn't win a title, so it wasn't a positive two tournaments. I had my chances in both.
"I lost in the semi-finals of both tournaments and just have to look forward to Indian Wells."