Roger Federer and Rafael Nadal, with 31 major titles between them, head for the US Open with their Grand Slam careers at the crossroads.
Despite turning 34, Federer was an impressive winner of the Cincinnati Masters title last weekend, seeing off world No.1 Novak Djokovic in the final.
It was the Swiss star’s 87th tour title and revenge for losing a second successive Wimbledon final to the Serb last month.
But Federer has stumbled badly in New York in recent years.
A five-time champion from 2004-2008, he was runner-up to Juan Martin del Potro in 2009 but hasn’t reached the final since.
His record at the Grand Slams in 2015 has also been mixed.
The seven-time Wimbledon champion may have at least reached the final at the All England Club, but that run was preceded by a shock third round exit to Italian journeyman Andreas Seppi at the Australian Open, his earliest in Melbourne for 14 years.
He then endured a quarter-final loss at the French Open to compatriot Stan Wawrinka.
Federer’s last Grand Slam title came at Wimbledon in 2012 and if he wins at Flushing Meadows, he’d become the oldest champion since 35-year-old Ken Rosewall back in 1970.
In contrast to the Swiss player’s staying power is Nadal’s swift, brutal decline.
The 29-year-old Spaniard, the 2010 and 2013 champion in New York, has endured a tough year, the knee joints and wrists looking stiffer and weaker.
After being deposed as French Open champion – his quarter-final loss to Djokovic was only his second ever defeat in Paris – Nadal slumped to 10 in the world, his lowest ranking for a decade.
He has recovered to eight, but is no longer the player that once struck terror into rivals.
Nadal has lost 14 times already this year compared to 11 in the whole of 2014, seven in 2013 and just six in 2012.
Djokovic already has the Australian Open and Wimbledon titles under his belt in 2015, taking his majors total to nine.
The US Open champion in 2011, Djokovic was runner-up in 2012 and 2013 before suffering a shock semi-final loss to Kei Nishikori 12 months ago.
The 28-year-old boasts a 56-5 record this year but two of those defeats have come this month – to Andy Murray in the Montreal Masters final – then against Federer in Cincinnati.
Murray, the world No.3, won in New York in 2012, ending Britain’s 76-year wait for a Grand Slam men’s singles champion and has made at least the quarter-finals in New York in the last four years.
The 28-year-old could set a record for the largest payout in tennis history at the US Open — $4.3 million.
That would be $3.3 million for winning the tournament and a $1 million bonus for winning the US Open Series title for performances in the hardcourt warm-up events.