Jenson Button is convinced ailing McLaren will one day challenge the might of Mercedes despite the two teams currently at opposite ends of the pace spectrum at present.

McLaren and new power-unit supplier Honda suffered abject humiliation in the season-opening grand prix in Australia earlier this month.

The team were already without the services of big-name acquisition Fernando Alonso after the Spaniard sustained concussion in a testing accident in Barcelona.

Come the race, reserve Kevin Magnussen failed to even make it to the start line due to a power-unit issue that forced the young Dane to pull over on the formation lap.

At least Button saw the chequered flag, describing it at the time as "a small victory", albeit finishing two laps down on race-winner Lewis Hamilton in 11th and last place.

Despite McLaren's seemingly hopeless position heading into Sunday's Malaysian Grand Prix, a positive Button can see hope on the horizon.

"We're a hell of a long way behind, but I feel we have something we can mould into something very special in the future, which is very exciting," said Button.

"Being 1.5 seconds off the pace and knowing you've peaked with your package, that's got to hurt.

"Whereas at least we have a glimmer of hope we can possibly challenge Mercedes one day."

Asked as to the reasoning behind his belief, Button replied: "The direction with the car in terms of aerodynamics, but also with how aggressive this engine is, which is why we're having so many issues.

"In many ways - it's probably wrong for me to say - it's probably more like a Mercedes than it is the other two manufacturers (Ferrari and Renault) in terms of design, aggressiveness and packaging.

"It's just going to take a little bit of time, but if we didn't have that hope you wouldn't see the strong effort by the whole team.

"They're not heading to races because they're paid to, they're doing so because they're passionate about racing.

"They're looking forward to the future as much as I am."

The one bonus for McLaren this weekend is Alonso is poised to return, pending a final medical check by the FIA at the Sepang International Circuit on Thursday.

Racing director Eric Boullier, for one, is happy to have the Spaniard back on board as he said: "I'm pleased to see Fernando back in the car.

"He's raring to go, and I know he's been working hard behind the scenes to prepare himself for this weekend." J