Roger Federer has revealed he struggled physically on the back of his quarter-final exit at the US Open.

The Swiss crashed out at Flushing Meadows to Juan Martin del Potro and having taken time off, is set to return for this week's Laver Cup exhibition event in Prague.

Federer has become an expert at resting his body in recent years, taking the second half of last season off before returning with wins at both the Australian Open and Wimbledon in 2017.

The 36-year-old was tipped to make it a hat-trick in New York but failed to beat Del Potro, going down 7-5 3-6 7-6 6-4.

Speaking on Wednesday, the 18-time Grand Slam champion admitted he struggled in the days after his defeat, suffering from a number of physical problems.

He said: "I was tired, lot of things in my body weren't right and I tried to take a rest and be ready for Laver Cup.

"(My) Back is doing well. I will try to practice every day until Friday when first matches will be played. I will give my best to be ready for every match."