Coach of the national football team Stanimir Stoilov said that the condition of forward Martin Petrov was worrying.
Petrov has knee problems resulting from a trauma.
Stoilov said that the practice session on June 5 will be determining for Petrovs participation in the Euro 2008 qualification match against Belarus on June 6.
On June 4, Petrov missed practice.
Focus news agency reported that Petrov will undergo medical exams on June 5. Previously, the forward stayed away from the field for nearly six months while recovering from trauma.
Bulgaria already met Belarus once in the Euro 2008 qualifications, registering a 2:0 victory.
Nearly 15 000 tickets for the second match between the two teams have already been sold. The match will take place at Sofias Vassil Levski stadium.
