Fernando Alonso says Mercedes is "racing in a different category" compared to the other teams in Formula 1 right now.
Ferrari brought an upgrade package to last weekend's Spanish Grand Prix, but Alonso could only finish sixth as Mercedes scored its fourth consecutive one-two finish and Red Bull got its cars home third and fourth.
The double world champion ended up nearly 90 seconds adrift of winner Lewis Hamilton - the biggest deficit of Alonso's season so far - while his Ferrari team-mate Kimi Raikkonen finished a lapped seventh.
Alonso has already conceded Mercedes is out of reach in the constructors' championship and said the best it could do this season was improve enough to make life trickier for the silver cars.
"This season has been so-so; we haven't been quick enough," Alonso admitted.
"We have been lapped in Spain, we were ninth and 10th in Bahrain, we are not on the first row of the grid, but we are third in the world championship.
"Apart from Mercedes that is racing in a different category, we are first or second [on any given weekend].
"There's not any prize for that, it just shows how competitive we are, whatever we have we will fight all the time.
"I know that the performance gap and points gap is quite big, [but] our job at the moment is to work hard on the car with all the team in Maranello, try to become a bit more competitive, and try to make things a little more difficult for Mercedes.
"First of all they win in front of everybody, they don't stress the car, they don't make mistakes, so the first step for us is to maybe not win but to not finish a minute behind them and complicate things a little for them."
Alonso has now gone a year without winning a race in F1, and it has been seven seasons since won his second world title for Renault, but the Spaniard reckons Ferrari still has what it takes to help him claim a third crown.
"I think we need to work hard, it was four points away in 2010 and three in 2012 so we've been close, let's hope we will have an opportunity again to fight for the championship and hopefully with the next one we won't miss it," Alonso added.
ALONSO'S 2014 SEASON IN NUMBERS
TRACK GRID TO POLE FINISH GAP TO WINNER Australia 5th +1.588s 4th +35.284s Malaysia 4th +0.744s 4th +35.992s Bahrain 9th +1.807s 9th +32.595s China 5th +1.777s 3rd +23.604s Spain 7th +1.908s 6th +1m27.743s
Autosport has produced a standalone special magazine to celebrate our 70th birthday. All current print subscribers will receive a copy for free. To order your copy of the 196-page Autosport 70th Anniversary issue, please go to: autosport.com/autosport70th