Roger Federer remains the "complete player", Rainer Schuettler has told Omnisport, as the Swiss maestro scales the ATP Rankings once more in record-breaking fashion.
Age is seemingly no barrier to the 36-year-old, who has begun 2018 by sealing a 20th grand slam singles title at the Australian Open and then returning to world number one thanks to his successful Rotterdam Open campaign last week.
Federer is the oldest man to become world number one - Andre Agassi had previously set the benchmark at 33 years.
Schuettler - a finalist in Melbourne in 2003 - was the world number six when Federer first topped the rankings in February 2004 and the German says an ability to adapt his game depending on opponent has been key to his mesmeric longevity.
"He is a complete player," Schuettler said. "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's renaissance over the past year has seen him add three grand slam titles to his haul, having previously gone five years without a major triumph as Novak Djokovic and Andy Murray began to dominate at the highest level.
The Swiss and his old foe Rafael Nadal have shared the last five slams between them, as well as topping the rankings, and Schuettler says Federer's comeback and likely continuation of his storied career only adds to his legend.
"When he returned everyone said that it's now the time of Novak and the younger ones," Schuettler 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."
10 de diciembre 2018
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|Klopp confirms 2013 talks with ´chatty´ Napoli president De Laurentiis|
|Sri Lanka spinner Dananjaya suspended due to illegal action|
|His reaction was just brilliant – Klopp praises Sterling for response to abuse|
|Gomez renewal a ´smart decision´ for both parties – Klopp|
|Magnificent Molinari named European Golfer of the Year|
|Barcelona best option for Frenkie de Jong, insists midfielder´s father|
|Gronkowski on Miami Miracle: ´Got to make that tackle´|
|Tottenham youngster Walker-Peters signs on until 2023|
|Juventus ´more of a family´ than Real Madrid - Ronaldo|
|Kingsley Coman contemplates retirement if injury nightmare continues|
|McVay ´sick´ over offensive failings as Rams coach takes blame for loss|
|Calleja axed as Villarreal coach|
|Kenyan Drake on Miami Miracle: I couldn´t let Gronk tackle me!|
|Ronaldo: I deserved Ballon d´Or, the numbers don´t lie|
|Rugby Australia to make Cheika decision this month|
|England defender Gomez signs new Liverpool deal|
|Ronaldo wants to see Messi follow him to Italy|
|Neymar happy to play in any position for PSG - Draxler|
|Paine insists he is ´fine´ after taking blow to finger|
|Ponzio: River players will be ´idolised´ for Libertadores success|
|Champions League permutations: How Inter, PSG and Liverpool can progress|
|Kohli: India were better and deserved to win|
|Bears shut down Goff, Rams|
|India survive dramatic finish against Australia|
|Klopp calls for electric Anfield atmosphere against Napoli|
|Saints clinch back-to-back NFC South titles, Bears trump Rams|
|Bucks improve to 2-0 against Raptors with win in Toronto|
|Black Caps include Patel for Sri Lanka Tests|
|Maidana: River want Real Madrid clash|
|Cowboys top Eagles in OT behind stellar Cooper display|
|AC Milan evaluating Fabregas signing – Leonardo|
|WATCH: Steelers´ chance at game-tying field goal slips away|
|Hayne will plead not guilty to charges, says lawyer|
|Boca boss Schelotto: The only thing I feel is sadness|
|Cardinals´ Fitzgerald makes NFL history with most receptions for one team|
|River Plate´s Copa Libertadores star Gonzalo Martinez confirms January departure|
|Klopp: I was never worried about Salah´s form|
|Packers QB Rodgers sets NFL record for most passes without an interception|
|World Cup bulking hampered Man United form – Lukaku|
|Leonardo rules out Ibrahimovic Milan return|
|Warriors´ Green to return against Timberwolves|
|I feel for him… we´ll make it work – Butler responds to Embiid´s frustration|
|Torino draw no missed opportunity for misfiring AC Milan, claims Gattuso|
9 de diciembre 2018
|We´ll always be linked together forever - Wade reflects on playing with James before final match-up|
|O´Sullivan wins record seventh UK title|
|Chiefs secure playoff berth, Saints win NFC South|
|River Plate 3 Boca Juniors 1 (aet, 5-3 agg): Quintero and Martinez clinch Libertadores title in extr|
|WATCH: Chiefs QB Mahomes throws no-look pass|
|Dolphins defeat Patriots on miraculous final play|
|Kizzire eagle snatches QBE Shootout victory|
|AC Milan 0 Torino 0: Donnarumma shines, Cutrone misses late chance|
|Back to the drawing board for West Indies - Chase|
|Copa Libertadores: Messi and Griezmann among stars in Madrid for River-Boca Superclasico|
|Brady sets NFL record for most career TD passes|
|Copa Libertadores: Tevez named on Boca bench for Superclasico final|
|Premier League needs VAR, right now! - Benitez fumes over Dean´s decisions|
|McCall expects Itoje to fit for the Six Nations|
|Solari salutes Real Madrid character after ´ugly´ Huesca win|
|Berbatov defends under-fire Lukaku|
|Sarries crush Blues to maintain unbeaten start|
|Newcastle United 1 Wolves 2: Doherty punishes Yedlin red with late winner|
|Deeney jokes he´ll ´smash´ former Watford star Richarlison|
|Huesca 0 Real Madrid 1: Bale ends drought as Solari´s men edge to victory|
|Ponting: Umpires not looking at no-balls|
|Bale ends longest LaLiga goal drought|
|Porter backs Brees for MVP, Saints for Super Bowl|
|Verstappen eyeing 2019 title fight|
|Wall ´shouldn´t have played´ against Cavaliers after scoring just one point|
|Hazard: Man City the best team in the Premier League despite Chelsea win|