Roger Federer was not surprised that Novak Djokovic struggled on his return from injury at the Indian Wells Masters, but backed his rival to quickly improve.
Djokovic was beaten 7-6 (7-3) 4-6 6-1 by qualifier Taro Daniel in one of the tournament's big shocks on Sunday, having been out of action since the Australian Open due to surgery on an elbow problem.
But world number one Federer, who won his own contest with Federico Delbonis, had expected that Djokovic would find it tough getting back into the swing of things on the ATP Tour.
"To me, it's not that surprising," the defending champion said in California. "When you go away from the game for a two-month period, it starts feeling a little bit that way.
"When you do come back from injury or when you haven't played in a long time, it just takes extra effort.
"It is still early stages for Novak coming back and the first one after surgery. He's only going to get better from here."
Federer's second-round match-up with Delbonis was delayed in the second set on Saturday due to rain, and the Swiss was intrigued by the opportunity to take on the same opponent for the second day running as he triumphed 6-3 7-6 (8-6).
"When you go from night to day [you are usually] playing a different opponent - so, naturally, it's all a change," said Federer.
"Whereas, here, now you play the same guy the next day, so you can really compare how different conditions are. It was actually quite interesting.
"The night-time is much deader. The surface doesn't react so much; the ball doesn't travel so fast."