His nation became the last to release their provisional squad with that 26 set for a training camp and a warm-up friendly with Spain in Villarreal on Sunday 3 June.
Coach Vladimir Petkovic will name his final 23-man squad the following day ahead of the competition where the Swiss will meet Brazil, Serbia and Costa Rica in Group E.
Fernandes is the least experienced outfield player in the squad – with just three caps to his name – all of which have ended in victory.
He could be one of four West Ham players at this summer’s tournament alongside Chicharito (Mexico), Cheikhou Kouyate (Senegal) and Manuel Lanzini (Argentina), while loanee Joao Mario (Portugal) is also Russia-bound.