McLaren and Honda have played down Fernando Alonso's claim that the decision to take an upgraded engine to Canada next weekend has already been taken.
The Anglo-Japanese team expected a more competitive weekend on the twisty streets of Monaco last weekend but Spaniard Alonso remains upbeat about what is coming.
"There is much room for improvement," sports daily Marca quotes him as saying.
"We're going to Canada with some improvements, particularly with the engine. Let's see if we start to use some tokens and can be more competitive."
However, McLaren team boss Eric Boullier denies that a decision has been taken, telling Marca: "About the engine in Canada? No, certainly not."
A Honda spokesman agreed: "It is not decided yet."
McLaren are seventh in the constructors' championship ahead of the race in Canada.