Lewis Hamilton admitted he was frustrated at failing to improve on his third place qualifying slot in Monaco after only finishing fifth on the streets of the principality.
Despite a difficult start, Hamilton maintained his place through the first stint of the race but failed to keep pace with Mark Webber and Nico Rosberg ahead.
Dropping behind Fernando Alonso when the pair pitted, Hamilton was also jumped by Sebastian Vettel when the defending champion then stopped, having run a longer first stint on the soft Pirelli tyre.
With overtaking proving to be impossible, Hamilton then found himself stuck in a train of cars through to the finish of the race with the Briton admitting afterwards that McLaren has work to do.
“I had a pretty poor start – I didn't understand why that happened – and I was lucky not to get caught up in the first-corner crash,” he said. “During the race, I struggled in the low-speed corners and found looking after the rear tyres tough. To make them last as long as we did, while trying to keep up with the pace of the guys in front, was one of the trickiest things I've had to do in a race.
“I lost time at my pitstop and gave away a place to Fernando, and then Sebastian was able to get past me after he made his own stop. After that, it was impossible to overtake. Today wasn't the best result for me – I really dislike going backwards in a race – but I think I got everything I could out of the car.
“We came away with some points, and there are many more races ahead, but we've definitely got some work to do because, race by race, we're struggling to keep up with the leaders. The other teams are picking up serious pace, too. We can't let them pull away from us – but we're a fantastic team, we'll knuckle down together, and we'll really push on now.”
Team boss Martin Whitmarsh was also disappointed with the way in which the race panned out.
“This year's Monaco Grand Prix won't go down as one of the most triumphant in McLaren's glorious Monte-Carlo history,” he said. “Although Lewis finished just four seconds behind Mark [Webber] today, in truth the smallness of that deficit was partly occasioned by the unique combination of the drivers' need to drive with tyre conservation in mind and a circuit on which overtaking is well-nigh impossible.
“As a consequence, Mark was able to back the field up in the closing stages, without risking his lead. Still, Lewis scored a useful ten points, and lies only 13 points off the drivers' world championship lead.”