Paul Hembery will not face the media in Montreal on Friday afternoon as he has withdrawn on advice from Pirelli's legal team.
Hembery was scheduled to attend Friday's FIA press conference for the Canadian GP along with Mercedes team boss Ross Brawn.
The duo were set to the focal point in light of the controversial post-Spanish Grand Prix test.
Mercedes spent three days testing in private with Pirelli, during which they ran a W04.
The two parties will face an FIA International Tribunal over the matter, prompting Hembery to pull out of Friday's press conference.
According to Autosport, "spokesperson for the Italian tyre company confirmed that lawyers had advised Hembery not to take part."
Brawn, however, will still attend.