Federer beat Nadal in four sets in his men’s singles semi-final at Wimbledon on Friday.
The Swiss, who was playing Nadal at SW19 for the first time in 11 years, will now play Novak Djokovic in his 12th career final on Sunday.
Henman and former French Open champion Sue Barker were discussing Federer’s performance after the match in the BBC studio.
Barker claimed Roger Federer’s plan would have been to keep the rallies as short as possible.
“I guess that was the game plan,” Barker said.
“At 37 years of age you don’t want to get involved in these long rallies, so it was ‘I’m going to go out and attack and that’s my Plan A’.”
Henman agreed but was amazed at how many long rallies Federer did end up winning against Rafael Nadal througout the match.
“I think if Federer goes into the press conference ‘yeah I wanted extended rallies because I felt like I was going to beat him from the back’ then we know he’s lying,” Henman said.
“But that was the amazing aspect.
“There must have been at least a dozen rallies that went 15 shots or more.
“I think the longest rally was 26, 27.
“I would say Federer won two thirds, maybe three quarters of them.
“That hasn’t happened against Nadal in the past.
“I think that will give him a lot of confidence because he’s now beaten an amazing champion.
“But he’s got the defending champion and World No 1 in the final on Sunday.”