Federer today dispatched Jan-Lennard Struff, brushing the big-serving German aside in less than two hours.

On Tuesday, he was even more comfortable against Aljaz Bedene in a match where Federer’s lack of banter with Will Ferrell was the biggest weakness the Swiss displayed.

But the world No 2, who is a 7/4 favourite with Betfair to take retain the title, insists there are players who can beat him all over the draw.

“I did say the first two matches you're going to see who's doing well and not so well,” Federer said, recalling that he had shunned the tag of favourite in the pre-tournament build-up.

“With Stan [Wawrinka. beaten in straight sets today], we saw he's definitely not at 100 per cent yet. 

“Novak [Djokovic] seems good to me, coming through the heat today. I think that was a good test for him. Should definitely give him confidence.

“[Alexander] Zverev seems also to be in good shape. Rafa [Nadal] the same.

“I think the suspects, the usual suspects, that we thought could win the tournament, seem to be around.

“Yeah, but there's definitely some guys missing, so the draw is going to have some openings.

“ [Juan Martin] Del Po[tro] is also in good shape.”

Del Potro failed to slip on a potential banana skin in the shape of 6ft 8in Karen Khachanov, whom he beat in four sets earlier today.

Should he beat Tomas Berdych in the third round, the Argentinian will be just one win away from a potential quarter-final against Federer, a match-up the Swiss is clearly already thinking about.

But Del Potro insists he is not looking as far ahead as the second week.

“First, I have to think about Berdych. Is going to be a difficult, difficult challenge to me,” Del Potro said.

“Tomas is one of the player who has the power to beat all the guys on tour.

“When he's feeling good, he's very dangerous guy.

“I will try to feel better for that match and then see if I am still winning.”