Resurgent Roger Federer has been hailed as a "complete player" by former Australian Open finalist Rainer Schuettler, who believes the world no.1 will not retire anytime soon provided he remains fit and continues to compete at the highest level.
Federer has enjoyed an excellent run since returning from knee surgery at the beginning of 2017, winning nine ATP titles and taking his tally of Grand Slam triumphs to 20 with back-to-back triumphs in Melbourne and a record-breaking eighth victory at Wimbledon.
The 36-year-old, who slipped to as low as 17th during that six-month period of inactivity, recorded the latest significant achievement of an illustrious career last week as his victory over Robin Haase in the quarter-finals of the Rotterdam Open saw him reclaim top spot in the ATP rankings from long-time rival Rafael Nadal, who has been nursing a hip injury.
He surpassed the mark set by Andre Agassi in the process and also overtook Serena Williams as the oldest no.1 in tennis history, male or female, in addition to ending his own five-and-a-half year absence from top spot.
After earlier wins over Ruben Bemelmans and Philipp Kohlschreiber, Federer went onto defeat Andreas Seppi and vanquish Grigor Dimitrov in under an hour in the final to seal his third victory in Rotterdam and move within 12 of Jimmy Connors' record of 109 men's singles titles.
"He is a complete player," retired former world no.5 Schuettler, who lost three of his four career meetings with Federer in Toulouse, Milan and Melbourne before beating him in Dubai in 2002, told Omnisport. "You see that, and this is very fascinating for me, against every player he has different tactics. He is selecting if he plays with deep slice, more spin, kick or more first serve.
"This is incredible, if he stays more in the back. How he is facing every match tactically, this is the impressive thing for me about his tennis."
Federer has carefully managed his schedule since recovering from that knee injury in order to aid his fitness and claims he will make a decision over whether or not to play at the Dubai Tennis Championships over the coming days before settling on a reduced clay-court schedule after the Miami Open next month.
Schuettler believes that Federer and Nadal's respective revivals during a period that looked set to be dominated by the likes of Novak Djokovic is a mark of the duo's enduring class and is hopeful that the veteran Swiss will be content to remain in the sport for the foreseeable future.
"When he returned everyone said that it's now the time of Novak and the younger ones," he added. "The way he came back is a great accomplishment and I am happy for him as well as for Rafa last year.
"This shows the quality of these two players. I think Roger has so much fun playing tennis so everything is possible. As long as he feels fit, as long as he knows he can compete with the best, maybe he won't retire that early. I think that everything is possible. I would be pleased if he stays much longer in tennis."