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."
|´#BetAgainstUs´ - Edelman and Pats embracing underdog status|
|Van der Vaart: Isco the best player in the world|
|I haven´t seen Guardiola or Klopp do that – Lampard unhappy with Bielsa|
|Real Madrid always play to win, insists Casemiro|
|Royals pitcher Skoglund suspended for 80 games after testing positive for PEDs|
|Ronaldo and Juve celebrate Supercoppa Italiana title with Mayweather|
|We are not going to talk about Morata - Simeone reluctant to discuss striker|
|Madrid weak in Leganes loss, says Solari|
|Bologna and Banvit seal Champions League play-off spots|
|LeBron James to miss Thunder & Rockets games but nearing practice return|
|Leganes 1 Real Madrid 0 (1-3 agg): Isco starts as Solari´s side go through despite defeat|
|NFL playoffs 2019: X-factor for each NFC team|
|Mahomes: Chiefs must not repeat mistakes against Patriots|
|Higuain´s Supercoppa benching due to virus, says Milan boss Gattuso|
|Brown fires back at Arians over ´diva´ comments|
|Stone heading home from West Indies tour with back injury|
|Shazier will continue rehab with intention of playing again|
|That´s why we signed him! Allegri hails Supercoppa match-winner Ronaldo|
|Monaco on worst home run in club´s history after Nice draw|
|Atletico Madrid 3 Girona 3 (4-4 agg): Simeone´s side out on away goals|
|Gregg Williams is Jets´ new defensive coordinator|
|Ronaldo: Supercoppa triumph just the start for Juve|
|Monaco confirm Batshuayi talks|
|You know more than me! Bielsa´s Barcelona research surprised Guardiola|
|Juventus 1 AC Milan 0: Ronaldo heads Bianconeri to Supercoppa glory|
|Kane injury cannot be excuse for Tottenham – Pochettino|
|Woods to open 2019 schedule at Torrey Pines|
|Reported Liverpool target Dabbur to undergo Sevilla medical|
|Lebanon v North Korea: Radulovic calls on players to make history|
|MLS MVP Martinez signs five-year contract with Atlanta|
|WBC set deadline for Wilder-Fury rematch|
|Iran 0 Iraq 0: Team Melli top Group D after dull draw|
|Vietnam 2 Yemen 0: Quang Hai shines to give Golden Dragons hope|
|Bielsa admits to spying on all Leeds´ opponents|
|Valverde open to arrivals amid De Jong tug-of-war|
|Sexton named in Ireland squad for Six Nations openers|
|Higuain benched for Supercoppa Italiana amid Chelsea links|
|De Grandhomme, Latham and Santner back in Black Caps squad|
|Oman v Turkmenistan: Verbeek tells players to ´score as many as possible´|
|Japan v Uzbekistan: Cuper not distracted by potential last-16 opponents|
|Brown desperate for England recall|
|Lowry ties course record in Abu Dhabi|
|James is playing for Bayern future – Kovac|
|Wizards can compete for playoffs in LeBron-less East despite injuries - Brooks|
|Kyrgyzstan 3 Philippines 1: Lux hat-trick gives White Falcons third-place hope|
|South Korea 2 China 0: Son sets the standard as Bento´s men take top spot|
|Saudi Arabia v Qatar: Top spot on the line in Group E|
|Wasps pull off Fekitoa coup|
|Fresh injury woe for Real Madrid defender Vallejo|
|Home sweet home for Wozniacki as Stephens conquers Melbourne demons|
|Nadal: Victory over Ebden a step forward|
|Proteas rest Steyn and De Kock for opening ODIs|
|Nadal and Federer march on as rising stars prosper|
|Barcelona president Bartomeu convinced Valverde will stay|
|Inter forward Keita suffers thigh injury|
|Nadal races into third round with easy Ebden win|
|Kimmich ´perfect´ for Barcelona, says Xavi|
|Richardson and Nabi inspire Renegades´ rout of Sixers|
|This Liverpool isn´t a team of chokers – Mane|
|Central Coast Mariners 2 Melbourne City 1: Late Simon winner ends 10-match losing streak|
|Bryan backs Murray to return after hip resurfacing surgery|
|Scotland coach Townsend turns to trio of uncapped hookers|
|Spurs´ Aurier arrested on suspicion of assault, released without charge|
|That was a fireworks show - Warriors revel in record-breaking first quarter|
|We are in talks with Chelsea – Salihamidzic reiterates interest in Hudson-Odoi|
|´Proud´ Messi recognises impact of team-mates after reaching 400 LaLiga goals|
|Henry v Vieira: The Arsene Wenger proteges to move into coaching|
|Federer enjoys ´cat and mouse´ win over Evans|
|Wozniacki cruises through in Melbourne|
|Federer maintains perfect Australian Open second-round record|