Jenson Button says McLaren has yet to run the updated Honda power unit at full power in Canada.
During Friday practice, Fernando Alonso was inside the top ten during FP1 as Button struggled with gearbox trouble, with the Spaniard saying a spot just outside Q3 is a realistic target for qualifying. Button, however, says he is still unsure of the potential of the updated power unit having not run it at full power.
"There’s a lot of work to do, but we weren’t running it where we thought we would be in terms of full power," Button said. "[On Saturday] you will see that we are more competitive."
Despite being convinced there is more to come, Button agrees with Alonso's assessment which puts Q3 out of realistic reach.
"I’ve got some things that aren’t quite right at the moment, so we will sort it out and then I will tell you. But we were not running where we should be with the power unit, but we will be [in qualifying].
"Top ten will be tricky. We’ll see, in FP2 with the rain coming people ran different fuel loads to normal. There’s a lot of work to do and a lot of room for improvement for both of us, I think."
Click here for Friday's gallery from the Canadian Grand Prix
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