MONTREAL (Reuters) - McLaren's Jenson Button, already starting last in Sunday's Canadian Formula One Grand Prix after missing qualifying, collected an additional drive through penalty after the team changed parts of his Honda power unit.
"JB's MGU-H and turbo have been replaced, hence he will have a drive-through penalty in this afternoon’s race," the team said on Twitter.
Button, winner in Canada in 2011, scored misfiring McLaren's first points of the season in Monaco two weeks ago when he finished eighth.
In 2011, he won a rain-affected race despite being in last place when the race was re-started. After passing Sebastian Vettel's Red Bull on the last lap, he described it as possibly the best victory of his career.
Button's team mate Fernando Alonso, who has yet to finish in the points this season, starts 13th but McLaren have no illusions about the task ahead.
Racing director Eric Boullier said on Saturday that McLaren, who have not won a race since 2012, needed to improve in all areas.
"If you want to win you have to be the best in terms of aerodynamics, vehicle dynamics, chassis, driveability, so we have to improve everywhere," the Frenchman said.
"We are lacking downforce to be at the front... so we have to work on this to make the car better."
Editing by Ed Osmond