The Vasil Levski national stadium, located in the centre of capital Sofia, is considered to be the only suitable arena for hosting such match in the Balkan country but Ludogorets will not be able to play there on August 27 or 28 due to a rock concert.
"I'm going mad," Ludogorets president Kiril Domuschiev told reporters. "I never thought that such a thing can stop us from playing in the Champions League (group stage)."
Razgrad based Ludogorets will be forced to play outside Bulgaria if they are drawn to host the playoff round's second leg. First leg will take place on August 20 or 21.
"There's an option to go and play in Romania (Razgrad is located some 70 km from the Romanian border), probably at the Steaua's (Bucharest) stadium," said Domuschiev. "But we could meet them in the playoff and then...
"There is a third option too - to play both matches away."
Ludogorets, who played at their 8,000-capacity Ludogorets Arena in the Champions League's qualifying rounds, were competing in the domestic third division only three years ago but won the league title in the last two seasons.
They knocked out Slovakian champions Slovan Bratislava and Serbian champions Partizan Belgrade to book their place in the playoff round.
The draw for the playoffs will take place in Nyon, Switzerland on Friday.
Most of the Bulgarian clubs face considerable infrastructure difficulties and are struggling to meet administrative, legal and financial conditions set by European soccer's governing body UEFA.
(Reporting by Angel Krasimirov, editing by Pritha Sarkar)
