Onana sees his relationship with the team as irreversible despite attempts from Cameroon Football Federation president and legendary striker Samuel Eto o to mediate peace talks.
Despite his call-up being somewhat of a shock, Martinelli has been in brilliant form this season, contributing five goals and two assists as Arsenal sit top of the table at Christmas.
Follow Sportsmail s live blog for all the latest news and updates as England kick-off their World Cup campaign, with Wales also in action this evening against USA.