This week's Madrid Open gives the streaking Serb a chance to achieve another first against Nadal, topping the world No. 1 on clay. Nine matches played, nine lost.
Madrid's high altitude, leading to faster conditions, will help Djokovic. Indeed, the closest Djokovic has come to downing Nadal on dirt was in the Spanish capital in 2009, when he couldn't take advantage of three match points in a bruising four-hour semifinal.
Here's a look at the men's top eight seeds:
No. 1 Rafael Nadal
Maybe, just maybe, Nadal might be tested early at a clay-court event.
His probable third-round opponent is Juan Martin del Potro, and the Argentine has come back faster -- than he thought -- from a serious wrist injury. Del Potro minimized his chances of success during the clay-court campaign, then proceeded to bounce Robin Soderling, again, en route to the final this weekend in Estoril.
With Roger Federer in Nadal's half, there's no repeat of last year's final. But we'd take a Rafa-Roger semi.
Nadal's current clay-court winning streak stands at 34.
No. 2 Novak Djokovic
Djokovic's winning streak to start 2011 sits at a lofty 26, and it should hit 27 by the time Sunday's Belgrade Open final is over.
Getting to 30 won't be without difficulty, though. Djokovic, if the seeds hold, would tangle with David Ferrer, the Spaniard who unfortunately landed Rafa in both the Monte Carlo and Barcelona finals.
If he passes that test, Djokovic and Nadal should meet in a third consecutive Masters Series final when both have participated.
No. 3 Roger Federer
With a disconcerting quarterfinal loss to Jurgen Melzer in Monte Carlo not far behind him, Federer has work to do before getting to Nadal.
To start, he must play either Feliciano Lopez or Milos Raonic. Lopez isn't known for having a stellar clay-court game, but the lefty is playing at home, and he advanced to the final in Belgrade. Raonic and his devastating serve are making good progress on clay. Tweaking his back in Estoril, though, wasn't encouraging.
No. 4 Andy Murray
Murray's quarter is lighter than Federer's, which is just as well since he's nursing an elbow injury that forced him to skip Barcelona. The ailment meant Monte Carlo, where he took a set off Nadal in the semis, wasn't a complete positive.
Murray's early threat stems from Florian Mayer, the German who has overcome his own injury woes. Mayer is in fine form, too, reaching Sunday's BMW Open final in Munich.
But the first priority for Murray is to make sure the elbow is OK.
No. 5 Robin Soderling
Soderling said he was 100 percent in Estoril after a bothersome Achilles and knee. But there's plenty of work to be done for the two-time French Open finalist, who's visibly short on confidence.
He might face his Australian Open conqueror, Alexandr Dolgopolov, in the second round. Dolgopolov is slumping, but he's bound to emerge sometime.
No. 6 David Ferrer
What are Ferrer's chances against Djokovic? The Spaniard has won all three of their clay-court meetings.
This, mind you, is a different Djokovic.
No. 7 Tomas Berdych
Berdych bailed from Barcelona due to illness. Presumably he'll be well rested for Madrid.
However, Berdych's potential first foe is Nikolay Davydenko. Slumping a week ago, Davydenko is Mayer's opposition in Munich, and when he's confident, look out.
Berdych has won two straight against Davydenko. Unfortunately for the reigning Wimbledon finalist, he'd lost nine in succession before then.
No. 8 Jurgen Melzer
Remember Andy Roddick? He's still around and lurks in the vicinity of his pal, Melzer.
But Melzer shouldn't be discounted. His win over Federer boosted his confidence, and the Austrian remains one of the game's most dazzling shot-makers.
Roddick won't be cursing his early-round draw on his least productive surface, paired with a qualifier in the first round. Should he advance, either Sam Querrey or Michael Llodra awaits in the second. Winnable. Given the Texan would likely play Melzer or Gasquet in the third round, he'd like his chances there.
The competitor Roddick is, he'd look forward to a tussle with Nadal in the quarterfinals.
London-based Ravi Ubha covers soccer and tennis for ESPN.com. You can follow him on Twitter.