Barcelona could suffer another shock loss to Russian opposition when they host Spartak Moscow in their opening Champions League group stage match Wednesday, coach Tito Vilanova warned Tuesday.
The last team to defeat Barcelona at Camp Nou in a European match were Russia's Rubin Kazan in 2009, having entered that match as underdogs much as Spartak do now.
"In the Champions League there are surprises and maybe Spartak can be one of those surprises for us," he said.
In the same year, Pep Guardiola's team had to fight back to beat Dynamo Kiev 2-1 in the Ukrainian capital.
"With Rubin and Dynamo Kiev we though that they were very easy matches. It turned out the other way round, they were very difficult," Vilanova said when asked about how he was approaching the Spartak clash.
Manchester United's defeat at the hands of Switzerland's FC Basel is another reminder of the threat supposed underdogs such as Spartak can pose, he said.
"Remember Basel and Man United. Any club can beat you," Vilanova said. "It's too early to say that we are favorites."
Spartak are coached by Unai Emery, who led Valencia to third in La Liga last season.
Emery's teams have not beaten Barcelona in 12 previous attempts, but Vilanova warned his fellow Spaniard could pose Barcelona plenty of problems.
"It was very hard for us, it was always very hard for us to play," Vilanova said of previous encounters with Emery's teams during his time as Guardiola's assistant.
"He's very brave, very decisive and we think Spartak will be the same [as Valencia], work on the same principle because he has his own style as a coach."
Vilanova is leading Barcelona into his first Champions League game as head coach after succeeding his former boss Guardiola at the end of last season.
