Rafael Nadal believes that the names of those implicated in the ongoing "Operation Puerto" trial into blood doping must be provided if the image of sportsmen and women in general is to be cleared up.
In an interview with the French sports daily L'Equipe published on Thursday, the Spanish tennis star said he felt his reputation, and that of Spanish sport as a whole, had been tarnished by the trial.
A judge has refused to demand that doctor Eufemiano Fuentes, the suspected mastermind of one of the sporting world's biggest blood doping rackets, provide the names of athletes implicated in the scandal.
The ruling could avert a huge fall-out from the high-profile trial in Madrid but Nadal said that naming names would have been the correct thing to do.
"What is happening in Spain, I don't understand it," he was quoted as saying. "I don't understand why doctor Fuentes is not giving names. And I don't understand why the judge has not asked him to do so.
"I don't understand why we never get to the bottom of these things. We need to clean everything up. I believe this doctor has worked with foreign athletes but because he is Spanish it is Spanish sport that is being prejudiced.
"As an athlete that hurts me. Because of people like (US cyclist Lance) Armstrong, we all have a dubious image."
Nadal, who made his comeback to competitive tennis this week at the Vina del Mar clay-court tournament in Chile, also admitted his relief at being back on the court after a lengthy injury absence.
But he said he did not expect to be back to his best until later in the season.
The former world number one returned after more than seven months out with a knee injury to beat qualifier Federico Delbonis 6-3, 6-2 in the second round.
He said before his return that his troublesome knee was still a source of nagging pain but he added that there was never any fear of a relapse.
"Fear? No. Stress, yes, that's to be expected. Relief and joy, certainly," he told L'Equipe of his feelings after his first singles match since a shock defeat to little-known Czech Lukas Rosol in the second round of Wimbledon last June.
"At the moment it's all about patience. I need to take things one step at a time and accept that I won't be at my maximum level straight away. I'm not scared because I know my knee is in good shape."
The Mallorcan will now face either compatriot Albert Montanes or another Spaniard Daniel Gimeno-Traver in the next round in Vina del Mar.
The tournament is all part of his preparations for the European clay-court season, and his bid for an eighth French Open crown.
"I want to be at 100 percent for Monte Carlo and the European clay season," he said. "Here in Chile, all that matters is how I feel and how my knee reacts. To lose here is not a problem. After so long out losing would be the logical thing."