Zenit St. Petersburg has traveled to Spain to take on Sevilla, which bookmakers have made favorite to win tonight's game at the Estadio Ramon Sanchez Pizjuan.
Zenit is currently in third place in the Russian Premier League after two matches of the new season, but Czech coach Vlastimil Petrzela said his team is already suffering fixture congestion.
"Our main problem is that we're playing every third day, and we have to make some quite serious adjustments for climate," he told the Zenit Web site. "We were in Siberia [to play Amkar Perm on Sunday], and now we have to deal with the heat. It's a problem."
Temperatures in Perm are currently around freezing, while Seville is enjoying up to 25 degrees Celsius.
Sevilla, fifth in the Primera Liga, is challenging for a berth in next season's Champions League, just two points behind fourth-placed Valencia. The Spanish club is likely to be without key players including Daniel and Jesus Navas (suspended) and the injured Airza Makukula, Ivica Dragutinovic, and Aitor Ocio.
Zenit will be at almost full strength, although Slovakian national-team goalkeeper Kamil Contofalsky is out with an injured shoulder and will be replaced by Russian international Vyacheslav Malafeyev.
The two clubs clashed earlier this season in the group stage of the UEFA Cup, when two goals from national-team striker Alexander Kerzhakov helped Zenit to a 2-1 win at the Russian side's Petrovsky Stadium.
Zenit is looking to continue Russian success in the UEFA Cup, following CSKA Moscow's triumph in the competition last year, when it beat Sporting Lisbon of Portugal to win in the final.
Zenit caused one of the biggest upsets in the tournament's recent history when it dumped out highly rated Marseille of France in the previous round. An Andrei Arshavin goal at the French giant's Stade Velodrome gave the Russian club a slender away victory, and a 1-1 draw at home was enough to see it through to the quarterfinals on aggregate.
The second leg of the tie will take place in St. Petersburg April 6.