Rotterdam - Roger Federer welcomed the return to tennis of Rafael Nadal, but will not spend much time worrying about his long-time rival's progress as he concentrates on his own game with a Wednesday start at the Rotterdam World Tennis.
While Federer was making his preparations, there was disappointment on court for third seed Jo-Wilfried Tsonga as the French player went down to Igor Sijsling of the Netherlands 7-6 (7/3), 4-6, 6-4.
Even 14 aces could not help Tsonga in the two-hour match, with the seed converting only one of eight break point chances.
Tsonga, a finalist here in 2011, saved a match point in the final game but lost his serve a few moments later to make a surprise first-round exit.
"This is not my worst moment, but I'm disappointed," said Tsonga. "I missed four or five of the same volleys on key points. That was the difference.
"He was serving very well and I was always chasing the score. I didn't play a bad match, just missed my chances. I was missing on shots that I usually make. But I will keep working hard and try to improve things."
Tsonga's s compatriot the fifth seeded Gilles Simon moved into the second round with a 7-6 (7/3), 6-4 victory over German qualifier Daniel Brands.
Romanian Victor Hanescu accounted for the week's first seed with his defeat of seventh-seeded Jerzy Janowicz 7-6 (7/4) 6-3. The Pole had made a breakthrough last autumn at Paris Bercy by reaching the final after coming through qualifying.
Grigor Dimitrov ended a four-match losing streak with a win over Australian Bernard Tomic 6-3, 3-6, 6-3.
Top seed Federer, defending his 2012 trophy said he has arrived relaxed and eager as he plays for the first time since losing a tight Australian Open semi-final to Andy Murray, then taking time off with his family in his homes in Dubai and Switzerland.
"I saw a few pictures of Rafa, last week," said Federer, who joked: "I see he's still a left-hander - and his shirts looked good."
But beyond the obvious natural curiosity, the 31-year-old with 17 Grand Slam titles has plenty on his own plate as he begins a run of events this week to be followed by the Dubai Open and the Indian Wells Masters next month in California.
"I'm happy to see him back and playing on the Tour," said the two-time Rotterdam champion.
"He seems to have good energy. I was surprised he lost a final against a player ranked outside the top 50.
"I'm sure he got a lot of information about his game last week (in Chile). He knows now how much strain he is putting on his body and how he is dealing with it."
After seven months away recovering from tendon damage in his left knee, Nadal lost both the singles and doubles finals at the VTR Open in Chile.
Singles winner Horacio Zeballos could only repeat what Nadal had been saying - that his comeback would need time.
While Nadal plays on clay in Sao Paulo, Federer will be bidding to make it a trophy hat-trick in Rotterdam, when he begins in the first round against Slovenian Grega Zemlja.