Jose Mourinho's Premiership titleholders tackle this second Group A tie buoyed by the possible return of skipper John Terry who was forced to miss Saturday's 2-0 win over Fulham due to a back problem.

Khalid Boulahrouz, who missed out on the Craven Cottage game with an eye infection, is expected to be fit and is favourite to step in to partner Ricardo Carvalho in the event that Terry's troubles return.

Terry has insisted now is the time for Chelsea to finally come good in Europe's top club competition.

"It's getting to the state where we have to win the Champions League. We can't keep saying: 'Next year will be our time'. We've got the experience and we've got the players."

Mourinho won't settle for anything less than a win in the Bulgarian capital ahead of next month's double-header against Barcelona.

"I need three points against Levski," was the Chelsea boss' succinct appraisal of the task ahead.

Chelsea, who failed to make it the quarterfinal stage of the competition last season, opened their campaign with a 2-0 win over Werder Bremen marked by Michael Ballack's first goal, a penalty, for the London giants since moving from Bayern Munich. Ballack had replaced Frank Lampard on spot kick duty after the England international's penalty miss against Charlton earlier this season.

But the midfielder stepped up to the plate in the suspended Ballack's absence at Craven Cottage and promptly underlined his return to form by firing in a second.

Lampard is one of only two surviving members of the Chelsea side that saw off Levski 2-0 in their last meeting in the 2001/02 UEFA Cup.

Terry, author of the opening goal that day, is the other.

Mourinho will presumably have his calculator handy to keep tabs on how many bookings his players pick up after his outburst at Bremen where he pointed to the four yellow cards handed out to his team as evidence of rough justice his band of millionaire players were receiving from referees.

The 'yellow card quartet' one booking away from missing Barcelona Act I are Terry, Lampard, Joe Cole and Didier Drogba.

Levski Sofia are enduring a baptism of fire on their Champions League debut with Chelsea's visit coming a fortnight after they were humbled 5-0 by titleholders Barcelona.

Stanimar Stoilov's side limbered up for this with a 3-0 win at Smolian to put them seven points clear in the league and despite the scale of the task ahead of them can take heart from Chelsea's poor away form with only one win from their last eight on the road.

"I'm sure the team will give their best. Everyone works for each other. We don't have big stars but we have a team and that's why we have done so well," said Stoilov.

"There is no pressure on us at all."