Hoffenheim spokesman Holger Tromp says that "it's not possible to give an outlook at this time."
Vukcevic is in an induced coma in a Heidelberg hospital after receiving life-threatening head injuries. The collision occurred on Friday afternoon between Hoffenheim and Heidelberg in southwestern Germany.
Vukcevic was airlifted to the hospital where the coma was induced after an operation. The truck driver received treatment for minor injuries.
Hoffenheim's Bundesliga game against Augsburg was to go ahead Saturday.
Hoffenheim general manager Andreas Mueller says the players "want to fight for him, because we know that's what he would have wanted."