The Swiss have a short programme of fixtures compared to many of their World Cup rivals, with just Peru left to face before their tournament gets underway against Ecuador on June 15.
It could be argued that the relative lack of preparation prevents Ottmar Hitzfeld's men from having the opportunity to slip out of the form that has seen them become one of international football's form sides over the past few years.
"Gavranovic now begins again with the running training and next week should be able to train with the team again," said the national coach, who is set to retire from football at the end of the tournament and will be replaced by Vladimir Petkovic.
And there was even better news of Barnetta, with Hitzfeld adding: "I'm assuming that he is fully fit again this weekend.
"The fact that we have a couple of ailing players is normal."
Jamaica, who will use this fixture as preparation for forthcoming Caribbean Cup and Copa America campaigns, have only once qualified for a World Cup - in 1998 - so Switzerland will surely view Friday's match as a chance to reacquaint themselves with their team-mates ahead of an undoubtedly tougher tie against Peru.
"We have trained incredibly intense in Weggis over the past four days," he added. "Competition is greater than four years ago before the World Cup in South Africa.
"We must lay the foundation for Brazil here."
