Jenson Button believes Daniel Ricciardo will present Mercedes with a challenge in Sunday's Chinese Grand Prix.

Ricciardo was quick throughout practice on Friday but behind Fernando Alonso in both FP1 and FP2. Having been asked if Ferrari could take the fight to Mercedes in Shanghai, Button acknowledged Alonso looks quick over one lap but said it was Ricciardo's long run pace which had caught his eye.

"I would say that the Ferrari probably isn't the car that will take it to Mercedes," Button said. "In qualifying maybe, but in the race, Ricciardo in the Red Bull looks very strong. He's a lot quicker than his team-mate and also able to do seven more laps I think on the long run. So he looks very good, the car is obviously working reasonably well in his hands so it's going to be a bit of a mix-up I think.

"A lot of it I think is that some people are getting the tyres working and some people aren't. You can see the big differences up and down the pit lane with graining and not graining."

McLaren was one team to be suffering heavily with graining, and asked if he was satisfied with the shape the team is in Button replied: "No, definitely not.

"There are a few things we can do overnight but I'm not sure we are quite as competitive as the last race here. But then again, in Bahrain we also struggled in P2 on the long run so maybe it will be better in the race."