Levski Sofia have their sights on a major upset when they host big-spending Chelsea at the Vasil Levski national stadium in the Champions League on Wednesday.

The odds of that happening in Levski's long-awaited home debut in the Champions League proper are slim looking at their performance in their Group A opener.

Levski did not make a start to remember with a 5-0 rout at the hands of European champions Barcelona at the Nou Camp two weeks ago.

Coach Stanimir Stoilov does not plan, however, to alter his tactics, saying: "I have no intention of changing our style of play.

"I'm an admirer of attacking football and we'll go out searching for goals from the very first minute.

"They are very good in set pieces but we can surprise them with some brilliant individual performances," he said.

Chelsea manager Jose Mourinho faces a big problem with the likely absence of England [Images] captain John Terry.

The first-pick central defender, who has a reputation for playing through injury, suffered a back problem in training last week and missed Saturday's 2-0 win at Fulham that took Chelsea to the top of the Premier League.  

Mourinho would not, however, rule Terry out completely.

"Today he is worse than yesterday, tomorrow maybe he is the same or better," Mourinho said after Saturday's game.

STRONGEST TEAM

Central defender Khalid Boulahrouz should return from illness to plug the central defensive gap alongside Ricardo Carvalho, allowing Paulo Ferreira to return to right back.

Mourinho is likely to stick with experienced Champions League campaigner Andriy Shevchenko though the 30 million pound ($57 million) striker has yet to shine for his new club.

Germany [Images] captain Michael Ballack [Images], suspended for three domestic games after being sent off last week, will also return in midfield.

Mourinho has indicated he will field his strongest available side despite Levski's status as the also-rans of Group A.

"We need the points," he said. Chelsea, who beat Werder Bremen 2-0 at home in their group opener, still have to face Barcelona at home and away.  

Mourinho would not, however, rule Terry out completely.

"Today he is worse than yesterday, tomorrow maybe he is the same or better," Mourinho said after Saturday's game.

Levski's Brazilian-born left back Lucio Vagner will return to their starting line-up after missing the defeat at Barcelona due to suspension.

With Valeri Domovchiyski struggling with injury and his strike partner Emil Angelov doubtful, Stoilov may turn to the Bulgarian premier league's top scorer Georgi Ivanov, who is yet to start in Europe this season.

Ivanov's double inspired Levski to a 3-0 win at lowly Rodopa Smolyan on Friday that took them to the top of the league.

A wave of euphoria has swept through Sofia before Chelsea's visit with match tickets sold out in less than five hours last Wednesday.

Probable teams:

Levski Sofia: 1-Georgi Petkov; 20-Stanislav Angelov, 4-Igor Tomasic, 11-Elin Topuzakov, 25-Lucio Vagner; 6-Richard Eromoigbe, 7-Daniel Borimirov, 27-Cedric Bardon, 21-Dimitar Telkiyski; 10-Hristo Yovov, 9-Georgi Ivanov.

Chelsea: 1-Petr Cech; 20-Paulo Ferreira, 6-Ricardo Carvalho, 9-Khalid Boulahrouz, 3-Ashley Cole; 5-Michael Essien, 4-Claude Makelele, 13-Michael Ballack, 8-Frank Lampard; 7-Andriy Shevchenko, 15-Didier Drogba.

Referee: Laurent Duhamel (France [Images]) (Additional reporting by Clare Lovell in London [Images])