Oh, for the days: Rafael Nadal in action at Wimbledon in 2008.

Another Wimbledon, another Rafael Nadal loss in the early rounds to a low-ranked serve-and-volleyer who’s destined to be a trivia answer in the Who did Rafa lose to? category. Dustin Brown this year, Nick Kyrgios the year before, Steve Darcis the year before that and Lukas Rosol the year before that. Except for Kyrgios, who has a mouth on him, none of these players is ever going to be a champ.

But Rafa is – was. What has happened to him? Is it age? (He’s 29 but then, Roger Federer’s 33.) His very physical game? A new racket? Loss of confidence and his famous mental toughness? All of the above?

Grass is a fast surface that requires players to move quickly behind a booming serve and sparkling net play. Everything happens in short bursts. It doesn’t favor long rallies from the baseline, a Rafa forte. Nor can he slide on grass the way he can on clay, taking some of the pressure off his Achilles’ knees. For these reasons, Rafa has always had far greater success on French Open clay than Wimbledon grass,. (There are players who have triumphed equally on both like Björn Borg, but he had a huge serve, which you need on grass.) It’s interesting to note that Rafa’s two Wimbledon wins came against Fed, a player he has owned (2008, the so-called greatest match ever) and Tomas Berdych, a solid player who nevertheless is not in the Fed-Rafa-Nole-Andy class (2010). Those wins seem like eons ago.

Will Rafa right the ship in time for the hard-court season and the US Open, which begins Aug. 29? It’s difficult to tell, because once your confidence is shot, losing becomes a self-fulfilling prophecy.

But Rafa has come back from so many injuries and from being eclipsed by Novak Djokovic as the No. 1 player in the world.

I wouldn’t count him out – yet.