Lewis Hamilton believes Mercedes's poor tyre strategy was a key factor in his failure to beat Sebastian Vettel and win the Malaysian Grand Prix.
Hamilton, 30, had to settle for second place behind Ferrari's Vettel after winning the season opener in Australia.
The Briton also bemoaned "confusing" radio communication from his team.
"It felt like it was lost at the first stop. We were a little bit quicker than them through some stints but it was too big a gap to close up," said Hamilton.
Vettel, who started second, took the lead when Mercedes chose to call in Hamilton for a pit stop during an early safety car period, while Ferrari left the German out on track.
Mercedes preferred to do the majority of the race on the slower hard tyre, finding it had greater resilience on their car.
But Vettel used the faster medium tyre for all but one stint and Hamilton was unable to get on terms.
"I guess perhaps we didn't expect so many cars to stay out and there were a lot of cars to get back through after the pit stop," added Hamilton.
"When I put the prime tyre on it did not feel good, it felt better on the option, we went back on the prime at the end but it really was not good."
Why was Hamilton unhappy?
Hamilton's frustrations at being unable to close the gap on Vettel were clear to hear during the race, with the Briton making his feelings known on the Mercedes team radio.
"I don't know what I'm supposed to be doing. Paddy [Lowe, Mercedes technical director] says I might be doing another stop," the world champion said on lap 40.
Three laps later he snapped: "Hey man, don't talk to me through the corners. I almost went off."
After the race, he said: "I remember there were some conversations going on, Paddy had pressed the wrong button and I could hear them yapping in my ear. He was asking 'am I going to do another stop'.
"I thought it was my last stop so it confused me, which was not helpful."
How did Rosberg feel about the tactics?
Team-mate Nico Rosberg also criticised Mercedes' tactics after he finished third.
The German, 29, was unhappy he was not told that his team-mate had switched tyres.
"After the first pit stop I was closing on Lewis at some point. Then he went for a pit stop and I never saw him again - he had disappeared in the distance," he said.
"How's that motivation? Then it turned out he was on a different tyre which I didn't know."
|BBC analyst David Coulthard|
|"Fair play to Nico for being so open and honest - but it's a bit confusing. Because there isn't that much to work out. You only have two compounds of tyres and you know where you stand with your team-mate. So it's either he's suddenly found turn of pace or is on softer tyres if he starts pulling away from you.|
|"We have all built Nico up as a thinker, the engineer behind the wheel, while pegging Lewis as the raw racer. But that interview exposes Nico to be vulnerable and confused."|