Roger Federer warned of Grigor Dimitrov US Open danger which involves Novak Djokovic

Roger Federer has been warned of the danger of facing Grigor Dimitrov in the US Open quarter-finals tonight by his former coach Paul Annacone.

Dimitrov has fallen down the world rankings over recent years but he looks to be on his way back with a strong run at Flushing Meadows.

The Bulgarian has enlisted the help of Djokovic’s former coaches Andre Agassi and Radek Stepanek – who know what it takes to beat Federer.

However, the pair are not in New York as they want Dimitrov to work on his game himself.

But they will still be offering him vital advice over the phone.

“I think that was extremely smart,” Annacone told the Tennis Channel. If Andre Agassi was around that was going to cause attention and focus.

“Also for Grigor to be able to learn and think through things.

“Somebody with that many tools needs to figure it out for himself.

“He has got a tough match-up, he is 7-0 against Roger and on the short side of that.

“And Roger has won 16 of the 18 sets they have played so it is a tough match-up.

“For Dimitrov, when you get on a role like this and you finally reboot the confidence and have everything to gain and nothing to lose there is a lot of danger.

“Roger will not take that lightly and he knows what he’s up against. It is going to make a shot makers delight that’s for sure.”

Meanwhile. Dimitrov is unfazed by the prospect of facing the 20-time Grand Slam winner.

“I don’t know. I mean, I know everybody on tour. There’s no difference,” he said.

“In the past we’ve played. We’ve practiced quite a bit against each other, especially in the past weeks. Played couple exhibitions here and there. Clearly we know each other pretty well.

“I don’t know. It’s a great moment to be at. I think it’s a great opportunity for both of us to be out here, I would say.

“It’s the US Open court. Hopefully we have a great battle and we can produce some great tennis.”