Belgian F1 GP: Hamilton says Red Bull, Ferrari closer to Mercedes

The reigning F1 world champion was second in both of Friday's practice sessions at Spa to team-mate Nico Rosberg, 0.242 seconds behind in the morning and 0.302s in the afternoon session punctuated by Rosberg's high-speed tyre blowout.

Red Bull's Daniel Ricciardo was third in both sessions, within 0.049s of Hamilton in first practice, before the margin grew on the soft compound.

With Ferrari also looming despite Sebastian Vettel failing to find a rhythm and ending the afternoon in 10th, Hamilton says he is expecting a challenge from both teams in Sunday's race.

"Red Bull and Ferrari are both looking faster this weekend than in past weekends," he said.

"It's going to be a close weekend, I'm up for a good fight this week."

While Rosberg felt he was "sort of one step ahead of Lewis", Hamilton said he was not worried about having to close the deficit to his team-mate.

"It's a very difficult track to have an advantage, particularly over the same car," he said.

"I think there's a little bit of time in Turn 1 [La Source] and I was losing a lot of speed on the two straights so it's essentially nothing to do with me.

"Otherwise, it's just small bits here and there."

MERCEDES GETTING 'EXCITED'

Despite ending the day as its closest challenger, Ricciardo insisted the Mercedes would be too quick for him to seriously challenge for back-to-back Spa victories.

"I think they're creating a little bit of excitement for themselves because normally they are their only threat, but we'll see," he said.

"I think we saw, even in the laptimes, they have still got half a second on us so there's still a big gap.

"Anything can happen around here but I'm not getting too excited."

Red Bull's form dipped during the soft tyre runs, with both Ricciardo and Daniil Kvyat lamenting a lack of rear grip.

It echoed a similar struggle during last month's British Grand Prix at Silverstone.

"It seems that it is hit and miss to be honest," Ricciardo surmised.

"The last couple of times with the option, we haven't found... you feel the grip but you can't really use it.

"You think you've got it but then it's a false sort of grip so we'll see what happens."