Rafael Nadal has hailed the brilliance of Alex de Minaur, calling him "a great player" after the Australian forced the Spanish legend to say an emotional farewell to the Barcelona Open, the beloved tournament he's won a dozen times.

Nadal made it clear after being outplayed 7-5 6-1 by de Minaur on Wednesday that this was going to be his last competitive performance on the court named after him at the Real Club de Tenis Barcelona.

But the 37-year-old, for whom this was a first tournament in three months and only his second in more than a year after being plagued with injuries, said he was delighted just to have been able to make his Barcelona farewell on the Pista Rafa Nadal.

"At least I had the chance to say goodbye here on court," Nadal said.

"That means a lot to me, because I felt one week ago that I was not able to play in this event.

"That would have been painful, so at least I played, I enjoyed the game, and now is the moment to keep going."

The Spaniard went down in typically battling fashion but world No.11 de Minaur was simply too sharp.

"Alex is a great player. In terms of tennis today, he was in better shape than me," said Nadal, who felt the Australian No.1 had made vast improvements since he last played him in a United Cup tie in Sydney - also won by de Minaur.

"He has really played at a very high level since the beginning of the season. He has made a very important step forward in his level of tennis.

"I'm just happy for him and I congratulate him for the level he played today."

Nadal showed some flashes of his old excellence and was left encouraged to believe that after his recent hip injury and abdominal issues he could be in much better shape to try to regain his French Open crown in May and June.

"I didn't practise a lot, so that performance encourages me to keep going," he said.

"It tells me that, if I'm able to spend days on the tour and keep practising with the players, I really hope and believe that I can keep being competitive if my body allows me to push the way that I need."

That's the big 'if' but there was a smile on Nadal's face as he congratulated de Minaur at the net.

"I feel much more comfortable and happier today than a week-and-a-half ago," Nadal, who won his first-round match against Italian Flavio Cobolli, said.

"I was able to manage to play two matches and played against a great player. I was not very far away, without a doubt.

"I hope and believe I can be competitive in a few weeks.

"That's the way that I need to proceed today, and to give me a chance to be ready at least to compete at Roland Garros."