Lewis Hamilton called for Mercedes to implement upgrades as soon as possible after a disappointing opening race at the Bahrain Grand Prix.

The seven-time world champion was well off the pace of the Red Bulls, who secured a one-two finish, and came fourth after losing his battle with former team-mate Fernando Alonso.

Aston Martin's show of strength is a particularly sore point for Mercedes, who supply their engine, gearbox and rear suspension, and fans may fear another tough season is on the cards for the team.

A disappointing campaign last term saw Mercedes respond to provide some competitiveness in the final rounds but Hamilton is keen for a much swifter reply this year.

"I thought the team did a great job in terms of pit stops and just unfortunately the car is not there at the moment," he told Sky Sports F1.

"We are just lacking downforce and we have got to work really hard to add that ASAP.

"Anything from in the wind tunnel, we need it tomorrow. We have really got to push massively to try and close that gap."

Team principal Toto Wolff is equally keen for developmental upgrades, but he feels a more radical approach is required.

The fact Aston Martin have impressed has provided some optimism, though, if the team can pinpoint where their success stems from.

"Red Bull is just on a different planet. That is what hurts because they are so far head, it reminds me of our best years because we just put a second on everybody else," he said.

"That is the benchmark and we have to do one step after the other to come back and we can do that. We can, absolutely we can.

"I think it needs to be much more radical in the steps than hope for a three-tenths upgrade.

"They [Aston Martin] deserve what they have done, they did a good job. The good news for us is there is a lot of Mercedes in there. To pinpoint it, that would be helpful in the recovery."