The rank outsiders will mix with Europe's soccer powerhouses only for a second time and the Bulgarian champions are in a group that also contains Paris St Germain and Arsenal.
"The worst is over," Stoyanov said on Monday, referring to Ludogorets's wins in the tournament's preliminary rounds.
"All we have to do now is to have fun. We'll show our best if we have fun," said the 29-year-old Stoyanov, who was voted Bulgaria’s Footballer of the Year in 2014.
Ludogorets secured their place in the group stage after eliminating three eastern European champions - Montenegro's Mladost Podgorica, Serbia's Red Star Belgrade and Czech Viktoria Plzen.
In 2014, Ludogorets finished bottom in a group, featuring Real Madrid, Liverpool and Basel in their maiden Champions League’s group stage appearance.
Stoyanov said Ludogorets need to make a positive start to be able to achieve their target.
"The first match in the group is important from a psychological point of view," Stoyanov said. "We know that Basel are a good team but we have no concern. We're totally relaxed."
Two years ago, Ludogorets beat Basel 1-0 to become the first Bulgarian team to register a Champions League group stage victory.
(Reporting by Angel Krasimirov; editing by Amlan Chakraborty)
