Still, as much motivation as Djokovic might have derived from that and as well as he played in their U.S. Open quarterfinal Thursday night, Roddick's own uncharacteristic serving miscues had a lot to do with the 2003 champion's 6-2, 6-3, 3-6, 7-6 (5) loss.
After working his way back from a huge deficit, Roddick was two points from forcing a fifth set at 5-4, 30-love in the fourth. But he double-faulted twice in a row and was broken for the fifth time -- twice more than he lost on serve in his first four matches combined.
"You know what? I honestly don't feel like they were super-tight doubles," Roddick said. "I had been playing pretty high-risk, high-reward tennis to get back and I probably wasn't about to stop."
But the first question Roddick was asked had to do with his verbal squabble with Djokovic, who took offense at comments the American made about how ill and injured the Serb was after the previous round.
"It was completely meant in jest," Roddick said. "I should know better. But listen, I joke all the time. I don't think anyone in their right mind takes me serious."
In Djokovic's prior match, a five-set ordeal Tuesday against No. 15 Tommy Robredo, the reigning Australian Open champion called for the trainer more than once as he dealt with hip, ankle, stomach and breathing issues.
Asked then about Djokovic's problems, Roddick kidded around, checking whether the list shouldn't also include bird flu, anthrax, SARS and a common cold and said: "He's either quick to call a trainer or he's the most courageous guy of all time."
What seemed to rile Djokovic the most were what Roddick said in an on-court interview that day: "I've got to feel good. He's got about 16 injuries right now."
After beating Roddick, ending the match with a 125 mph serve that drew a long return, Djokovic made reference to those words.
"That's not nice anyhow to say in front of this crowd that I have 16 injuries and that I'm faking," Djokovic said during a postmatch interview that drew boos from the spectators in Arthur Ashe Stadium.
"They're already against me, because they think I'm faking everything," he said.
The third-seeded Djokovic advanced to a semifinal meeting against Roger Federer. It's a rematch of last year's U.S. Open final, which Federer won for his fourth consecutive title at Flushing Meadows.
Federer -- bidding for a 13th major title, one shy of Pete Sampras' record -- beat qualifier Gilles Muller 7-6 (5), 6-4, 7-6 (5), extending his own record by reaching the semifinals at an 18th consecutive Grand Slam tournament.
Djokovic is 2-6 against Federer and called him the "absolute favorite."
Against Roddick, Djokovic grew increasingly agitated when spectators called out as he was trying to serve or in the middle of points.
With Djokovic serving at 3-3 in the fourth set, he watched Roddick's backhand winner fly past to set up break point and yelled "Shut up!" in the direction of the stands before cursing. Roddick followed with another backhand winner to cap a 12-stroke exchange and take the lead in the set.
But he couldn't hold it.
Serving at 5-4, having held nine times in a row, Roddick opened with a 142 mph ace and a 143 mph service winner. At 30-love, he was two points from being all tied up.
And right there, all so suddenly, everything came apart.
First, Roddick pushed a forehand wide. The he double-faulted, not once but twice, to hand over a break point. And Djokovic didn't let the opportunity pass by, delivering a perfect lob winner to get to 5-5.
The set went to a tiebreak, and at 5-5 there, the players settled into a 15-stroke point at the baseline that concluded when Roddick missed a backhand slice into the net. Seconds later, the match was over, and Djokovic was pounding his fists on his chest.
And only moments after that, he was inciting boos.
The men's semifinals and women's final are all scheduled for Saturday, but tournament organizers have seen forecasts calling for about 12 hours of rain and wind at up to 35 mph that day. So they began the process of negotiating with TV networks and preparing contingency plans, including weighing the possibility of announcing Friday that no tennis would be played Saturday and that the men's final would be shifted from Sunday to Monday.
Federer spent a record 237 consecutive weeks atop the rankings from February 2004 until last month, when Nadal supplanted him. That's only one of several streaks Federer has seen snapped in 2008.
He reached a record 10 consecutive major finals, until losing to Djokovic in the Australian Open semifinals in January. He won a record-tying five consecutive Wimbledon titles, until losing a 9-7 fifth set to Nadal in near-darkness in July. He was seeded No. 1 at 18 consecutive Grand Slam tournaments, until Nadal relegated him to No. 2 at this one.
"There's a lot at stake for him, obviously, as far as, you know, not having won a major this year and losing a No. 1 ranking. So he seems to be obviously very focused and is playing better," said Patrick McEnroe, the U.S. Davis Cup captain who is also coaching Roddick.
"I don't think he's playing quite at the level that he was in the last couple years," McEnroe added, "but he's certainly capable of turning it around."
On Thursday, as the break points and the set points slipped away, as his shouts of self-admonishment grew louder, it was hard to imagine Federer was having this tough a time in his quarterfinal against a man ranked 130th.
A man who arrived at Flushing Meadows with a 3-4 tour record this year.
A man who was kicked out of his hotel because it didn't occur to him to book a room long enough to stay past the third round of a Grand Slam tournament for the first time.
Fans used to watch Federer hoping to be awed by his brilliance. Now they wonder: Is he going to hang on? For the most part, even during this poor-by-his-standards season, he does get by. Federer did just that against Muller.
"He created a monster, like he said a couple years ago. He won everything. And now everybody expects him to win everything, and, I mean, he's also just human," Muller said. "Even today ... you could still see why he was No. 1 -- and still No. 2 now. Every time the score was tied, he came up with a better shot."
It was Federer's 32nd straight victory at the U.S. Open, where he has won the past four championships. The only man to have won more matches or titles in a row at this tournament was Bill Tilden in the 1920s.
Federer spoke proudly of his run of major semifinals; no other man ever topped 10.
"A huge streak," he said. "I hope this time around I can take it a step further than I did in Paris or Wimbledon."
See? Even he focuses on his missteps, making reference there to his losses to Nadal in the past two Grand Slam finals.
Trailing 4-1 in the final tiebreak against Muller, Federer took six of the final seven points, including a cross-court backhand passing shot to get to match point. It was the sort of spectacular stroke Federer often produces, but he marked this one with a loud shout of "Come on!"
When Muller put a backhand into the net on the next point, the tighter-than-expected match was over and Federer could finally leap in the air and scream again. He let out several yelps during the afternoon, sometimes in anger, sometimes in delight, and sometimes it was tough to understand in which language (Swiss German, French or English). Once, he let out a high-pitched "Woooo!"
A more combustible Federer has been on display throughout this U.S. Open. A less overpowering Federer has been on display throughout this season.
"I guess for a while I put my head down in the matches and just tried to keep that unbelievable run I had going instead of trying to disturb myself with, you know, any sort of reactions really," he acknowledged.
"Who knows? Maybe it is just a couple of weeks, and I'm going crazy, and after that you'll see me more relaxed again," he said.
He insisted afterward that he was frustrated more by the wind and sun in Arthur Ashe Stadium than by his inability to take advantage of any of the first six set points he earned in the opener. Or by the 10 break points he wasted in the match.
Muller's assessment of both men's play?
"The level was not that high," he said.
Muller dropped to 0-1 in Grand Slam quarterfinals, while Federer is 20-2.
Past performances aside, Muller felt as though he could win, which isn't necessarily how most opponents approached matches against Federer in recent years.
"On the court, nobody should have respect for him. You just go out there to win, no matter who is on the other side of the court," Muller said, adding a few moments later: "A lot of people think that I should be happy, but actually I'm disappointed, because I think today I had my chances -- and I didn't take them."