Following criticism of the four-stop strategies seen at times early this season, the Italian marque wanted to make more radical changes for Canada this weekend.
Instead, only a minor tweak will be tested on Friday morning, and pending the agreement of the teams, the change - to solve the rear delamination problems seen this year - could be introduced for the British grand prix late this month.
But beyond that, motor sport chief Hembery acknowledged that the necessity for the unanimous vote of the teams makes more changes in 2013 very unlikely.
"Ideally we'd like to change the harder compound to give us more guarantees of being under three stops," he is quoted by PA Sport news agency.
"But that sort of change needs the agreement of all 11 teams. Teams have taken different design approaches, so some feel they don't wish to be penalised by an in-season change that may alter their performance levels," he added.
Meanwhile, the German newspaper Hamburger Morgenpost has published photos of Nico Rosberg's Monaco-spec car depicting right-side Pirelli tyres fitted on the left of his Mercedes.
The 20min.ch website said Mercedes has confirmed the veracity of the images, saying the rules allow the practice, which has also been deployed by other teams in 2013.