Ciprian Marica missed Wednesday's training session for Romania as he continues to recover from a concussion he suffered in training a day earlier, reported dpa.
The 22-year-old striker sustained the concussion going for a header with teammate Marius Nicolae and was taken to hospital in St Gallen as a precautionary measure.
VfB Stuttgart's Marica was not fielded in Monday's 0-0 draw with France and is considered a serious doubt for his country's second Group C match against world champions Italy. Romania's other opponent in the tough group is the Netherlands.
Although the general secretary of the Romania football federation, Ioan Lupescu said after the incident that the player was fine, Romanian media has reported that it will be decided in the coming days whether Marica plays any further part in the tournament or if he should return home.