The 19-time Grand Slam champion beat Richard Gasquet 6-2 7-5 6-4 to progress to the last 16 at the Australian Open on Saturday.
And it was way Federer glided round the court that impressed Eurosport pundit Croft the most.
She said: “There are very few players who can make Roger Federer uncomfortable out there.
“We just saw little glimpses of it but he did cope with those moments and he slams the door shut so very quickly.
“I just think his level is higher than we’ve ever seen and it’s so hard to believe at 36 that’s what we’re saying about the movement and the variety he’s bringing out on to court.
“That footwork is so light. The footwork around the ball, he almost floats across the court.”
Croft’s fellow pundit Greg Rusedski agreed with the praise and said: “If you look at what he did, the control and the movement was just so exceptional.
“Federer just does everything that much better than Gasquet.
“There’s two players who I consider great movers – Federer and Djokovic – but I’ve never seen a 36-year-old move like that.
“I’d like to have moved like that when I was in my twenties.”