Saborio fractured a metatarsal in his right foot during national team training in Costa Rica on Thursday and head coach Jorge Luis Pinto confirmed the 32-year-old will miss up to four months.
The Real Salt Lake striker, who has netted 32 goals in 93 appearances for Costa Rica, was included in Pinto's preliminary squad and was expected to play a big part in Brazil, where the team will come up against heavyweights Italy, England and Uruguay in Group D, but he will now sit out the showpiece event.
"I feel really sorry for him, he is an extraordinary man," Pinto told reporters.
"The group is hit, Alvaro is a leader and that certainly hits all. I hope footballing speaking we can replace it, although it will not be easy."
It is another blow for Costa Rica, who are already without the services of Everton star Bryan Oviedo after he failed to recover from a broken leg.
