Roger Federer does not know what to expect when he faces Novak Djokovic for the first time in two and a half years in Sunday's Cincinnati Masters final.
The pair last met in the 2016 Australian Open semi-final, Djokovic prevailing over four sets before going on to claim a sixth title at Melbourne Park.
Injuries for both men in the intervening period mean tennis fans have been deprived of another instalment of one of the sport's great rivalries, Djokovic edging the head-to-head record 23-22.
And Federer - seeking his eighth crown in Cincinnati, having defeated Djokovic in the final three times - is relishing another showdown with his old foe.
"I think what's nice about this, it's like fresh," Federer said after coming through his semi-final against David Goffin, who retired in the second set with shoulder problems on Saturday.
"It's not like we have played in the last few weeks and everybody knows what to expect. We know how we could look like, but we're not quite sure, the fans, you guys, us as well to be honest.
"A lot has happened since, with injuries both of us have been fighting, and we both came back strong again. So I think that's what's nice about this time around with Novak in the match.
The Men's Final is SET:— Western & Southern Open (@CincyTennis) August 19, 2018
World No.2 Roger Federer versus No.10 Novak Djokovic.
Who will claim the coveted crown? pic.twitter.com/iaqiXWHcSZ
"When they asked me in Indian Wells and Miami to judge Novak, I was like, 'It's not the real Novak.' He was just coming back, and he came back too soon. Same at the Australian Open. That one wasn't quite the 100 per cent Novak we know he can be.
"So I don't look at that kind of match like what could he be struggling with, because if you give him time, he'll fix that. Same with Stan [Wawrinka]. If he's got time, they will fix that. They will be very different players three months down the road.
"And look what happened after the French [Open]. Everything turned. He could have won Queen's, should have won Queen's, maybe. He ends up winning Wimbledon and he's back in another final. It looks like he hasn't missed any tennis at all over the last few years.
"I think it gives him a lot of confidence winning all those three-setters now, because in Indian Wells and Miami, what I saw there was a tired Novak, which was very rare to see. But that's why it wasn't real. He hadn't had enough practice yet, still coming fresh off his injury.
"So I think he's playing much better tennis now, much more solid off the baseline. I still think he's got room to improve. It will be interesting to see how he finishes the year."
|Rockets rout Warriors as Green goes scoreless|
|Seahawks rally past Packers|
|Lakers G Rondo to miss 4-5 weeks|
|Durant is done with questions about Green|
|Smith, Warner set to return to IPL in 2019|
|No rivalry between Mbappe and Griezmann – Deschamps|
|Neymar: Emery will bring success to Arsenal|
|Jedvaj backs Croatia to deliver against England|
|Howell grabs first-round lead at Sea Island|
|Rooney backing Kane to break England record|
|Betts named American League MVP|
|Republic of Ireland must improve, says under-pressure O´Neill|
|Injured Sergio Ramos to leave Spain squad|
|Yelich named National League MVP|
|Low praises ´beautiful goals´ from Sane and Gnabry|
|Belgium boss Martinez pleased with patient Batshuayi|
|Wilson and Sancho pay tribute to England ´legend´ Rooney|
|Rooney gave England squad a lesson in humility - Southgate|
|This Week in U.S. Sports: LeBron passes Chamberlain, Williamson looking like he is next|
|We still have a chance - Luis Enrique not giving up hope after Spain defeat|
|Rockets ´parting ways´ with Anthony|
|Rooney became ´embarrassed´ at Manchester United|
|Federer: ´Easier´ to play when I´m up against it|
|Rooney convinced England are in safe hands with Southgate|
|Black Caps skipper Williamson confident over first Test availability|
|Federer cruises into last four of ATP Finals for 15th time|
|Republic of Ireland 0 Northern Ireland 0: Randolph saves light up bore draw|
|England 3 United States 0: Experimental side impresses on Rooney farewell|
|Croatia 3 Spain 2: Jedvaj keeps World Cup finalists in contention|
|Belgium 2 Iceland 0: Batshuayi rekindles Hazard flame with match-winning brace|
|Germany 3 Russia 0: Sane on target as Low´s men stroll|
|´Fancy taking a look at Brexit?´ - Southampton credit Austin with VAR breakthrough|
|Green: Altercation with Durant will make Warriors stronger|
|Juventus star Dybala dismisses Manchester United links|
|Strinic given all clear to return to AC Milan training|
|Papier wait over as scrum-half starts for Springboks|
|MLB commissioner Manfred gets five-year extension|
|South Africa international Du Preez joins brother at Sale|
|Pogba and Sterling support my football dream, says Bolt|
|Asensio wants to ´feel more important´ at Real Madrid|
|Former Roosters and Cowboys centre Linnett joins Hull KR|
|New team tournament ATP Cup wins Djokovic´s approval|
|Roma and Pallotta donate €150,000 to injured Liverpool fan Sean Cox|
|England captain Root reprimanded on frustrating day in Pallekele|
|Jokanovic proud of establishing Fulham´s ´footballing identity´|
|Huget to make first France appearance in a year|
|Mourinho and squad ´united´ despite ´mixed´ start, says Woodward|
|Petaia and Gordon to make Wallabies debuts in Padova|
|Barcelona star Arthur determined not to let Xavi praise go to his head|
|Youthful Netherlands have forged strong bond - Wijnaldum|
|Premier League confirms £5m package for departing chief Scudamore|
|Thiem blasts past Nishikori to keep semi-final hopes alive|
|He´s always got time for me – Gerrard loved learning from Liverpool boss Klopp|
|Kearney and Ringrose return for All Blacks clash|
|Molinari on course for Race to Dubai title, Smith and Otaegui lead|
|Premier League to implement VAR from 2019-20 season|
|FSF urges Premier League clubs to reject Scudamore ´golden handshake´ request|
|Rhinos pull off Merrin coup|
|Ribery apologises for reporter altercation|
|Ford to captain much-changed England, Cokanasiga starts|
|Crotty replaces injured Williams for Ireland showdown|
|Classy Roshen gives Sri Lanka unlikely lead|
|Injured Lukaku out of Belgium-Iceland Nations League clash|
|Rooney ´passionate´ about future coaching career|
|Mehidy spins Tigers to victory despite second Taylor hundred|
|Rooney deserves special England day - Antonio|
|LeBron thinks back to his roots after latest milestone|
|Messi to return for Argentina next year - General manager Burruchaga|
|Walton salutes LeBron after he surpasses Chamberlain|
|Croatia´s Dalic and Modric not out for Spain revenge|