Lewis Hamilton believes Red Bull has a "stunning car" that will definitely be a frontrunner once the reigning Formula 1 champion team gets its reliability issues under control.
While Red Bull has struggled with mechanical problems throughout 2014 pre-season testing, Hamilton's Mercedes team has led the way in terms of mileage and often in terms of pace as well.
But the 2008 world champion does not expect Red Bull to be behind for long, and he was full of praise for the RB10's design.
Hamilton tops final day of Bahrain testing
"They look like they have a stunning car, and usually the more beautiful it is the faster it is so I'm sure they've got a pretty quick car this year," Hamilton said in the Bahrain paddock on Sunday night.
"Once they get the engine sorted, or the systems that they might be struggling with, I think they'll - as always - be very hard to beat.
"Sebastian [Vettel] is the reigning world champion so he's the target for everyone.
"But I know my team is strong so hopefully we'll be able to fight with them."
Hamilton added that the 2014 pre-season was like no other he had experienced, and he warned that there is "a lot more to come" from the Mercedes after he did not get the most out of the super-soft tyre at the end of the day.
Bahrain F1 testing gallery
"It's definitely the weirdest and most difficult pre-season to be able to judge where everyone is," he said.
"There's still things we're learning, things we haven't covered, there's tonnes of stuff.
"So as we go into the race weekend it will be a bit like a test on the Friday. I think there's a lot more to come.
"There will be mistakes through the whole paddock I'm sure, and hopefully we'll make the least."