Jenson Button has insisted McLaren-Honda have not had a terrible season, despite both the former world champion and his team-mate Fernando Alonso retiring from the Canadian Grand Prix.

McLaren re-united with Honda at the start of the season, having had engines supplied by Mercedes beforehand, but the Woking outfit have endured a testing F1 season - Button picking up only four points from the seven races so far, and Alonso winning none since joining from Ferrari. 

Button started at the back of a grid before a drive-through penalty forced him further behind. After being lapped by winner Lewis Hamilton after just 20 laps, Button was forced to follow Alonso into the garage on lap 58 with a cracked exhaust.

It was an equally as wretched afternoon for Alonso, who complained over the radio that the team risked "looking like amateurs" if they slowed down to save fuel, before being forced to retire on lap 43 at Circuit Gilles Villeneuve.   

But 2009 world champion Button insisted that McLaren-Honda have not underperformed in 2015, despite admitting it had been a frustrating weekend in Montreal.

"I'm going to go and have a nice meal and reflect on today," he said. "It was obviously a difficult day. For me it was obviously made more difficult by starting last and then having a drive-through.

"You're out of sequence and the leaders lap you, pull away, then they pit and they lap you again. You lose so much time.

"One of our biggest issues was fuel saving around the lap, and then you use tyre temperature as well. Everyone fuel saves, but if you don't have the straight-line speed you use more fuel because you are on the straight for longer.

"So maybe some of it is efficiency, maybe we're running too much downforce or something, but it's something we need to solve for the next one because the next one's also quite tough with straights. Not as bad as here, but still it's going to be a tricky one for us."

Button enjoyed his first finish inside the points at Monaco, coming 8th - but enjoyed a less successful weekend altogether in Canada, after an ERS-related failure during the final practice meant he missed qualifying.

The Englishman's troubles were only compounded after he completed a double retirement for McLaren on Sunday.

"Today was quite painful," Button admitted. "Monaco was a good weekend, so I'm quite happy I scored points there, but I think it's unfair to say it's been a bad season except for Monaco because we've been improving almost every race with at least one of the cars.

"So there's been improvement all the way except for today, but it was always going to be tough for us with the layout of the circuit. Hopefully we'll be back on track in Austia when we will have some updates. 

"It's easy to look at it and say 'oh, it's a terrible season for McLaren-Honda' but it's not just the case. We've improved massively this year and I think we should be happy with what we've done. But you do have difficult days."

He added: "We are a long way behind in terms of development but if you don't take a stab with a new project like this, you are never going to fight the top guys.

"There is no way someone else with a Mercedes engine can win the world championship. Ferrari possibly can and so can we. So we had to see."

McLaren's chief operating officer Jonathan Neale insisted that they were right to leave their previous relationship with Mercedes.

"If we'd stayed with Mercedes, there is not a cat in hell's chance we would have beaten them," he told BBC Sport. "I love Toto Wolff and Paddy Lowe like a brother but they are not going to share data with us.

"We have to be independent. We are going to fight this as a team. The only way back to championships is with an independent. Honda have done a great job in a short period of time."