Novak Djokovic says Roger Federer isn't moving as well this year

Novak Djokovic played Roger Federer for the first time this season in the Paris Masters semifinals. (Clive Brunskill/Getty Images)

LONDON -- Novak Djokovic hadn't faced Roger Federer all year before beating him 4-6, 6-3, 6-2 in the semifinals of the Paris Masters on Saturday. Before their rematch Tuesday at the ATP World Tour Finals, Djokovic was asked about Federer's subpar season.

"From my point of view, he hasn't been moving as well this year as he did before," Djokovic said. "I guess that's one of the reasons why he hasn't had as much success this year."

Djokovic went on to defeat Federer 6-4, 6-7 (2), 6-2 in their first round of group play at the season-ending Tour Finals. The Serb moved within one victory of evening the head-to-head with Federer, who leads 16-15.

"[H]e's Roger Federer," Djokovic said before the match. "He's achieved so much in his career and he's never to be underestimated as long as he plays tennis. He has incredible quality in his game and even though he is moving maybe slower than he used to, he's still striking the ball really well. If he feels well that day, then he's dangerous."