That is the opinion of former British No 1 and Sky Sports tennis pundit Annabel Croft.
Federer has won his last five matches against old foe Nadal, with four of them coming in 2017.
Three of the victories have come in finals, including a five-setter at the Australian Open in January.
Federer also beat Nadal at the final of the Miami Open in April and Shanghai Open in October.
Ahead of Nadal’s first match at the ATP World Tour Finals against David Goffin tonight (8pm), Croft was discussing the Spaniard’s injury problems.
The 31-year-old comes into the event with a knee problem that forced him to withdraw from the Paris Masters two weeks ago.
Croft says that it is a shame his participation in the season-ender is in doubt but says losses to Federer have also had an impact.
“It’s such a shame isn’t it, after such an incredible season, six titles, two more Grand Slams,” she said.
“But I do think those four losses to Roger Federer have really hurt as well.”
Federer is the favourite to land the tournament for a seventh time this week.
He started his campaign with a straight sets win over American Jack Sock yesterday.
He faces Alexander Zverev next tomorrow evening (8pm).