LISBON - Jose Mourinho takes Chelsea to one of his former employers on Tuesday as the Londoners attempt to break Sporting Lisbon's impressive 16-game home unbeaten run in European competition.
The respective capital clubs clash for the first time at the Estadio Jose Alvalade in a key Champions League fixture with all four teams in Group G locked on one point after one round of the six match pool phase.
Slovenian side MK Maribor, who salvaged a late equaliser against Sporting on September 17, travel to Schalke in the second Group G showdown in Germany.
While Chelsea have produced almost flawless domestic form and have raced to an early three-point lead in the Premier League on the back of new signing Diego Costa's eight goals in six matches, they looked far from their best in their Stamford Bridge opener against Schalke.
Despite leading for much of the match, an early Cesc Fabregas goal failed to stand up and a swift counter attack in the 62nd minute led to a Klaas-Jan Huntelaar equaliser against the 2012 European champions.
Mourinho, who worked under the legendary Bobby Robson as an assistant at Sporting between 1992 and 1993, knows defeat against last season's Portuguese runners-up could compromise their chances of qualifying for the knockout phase.
Victory and the road opens up to winning the group with back-to-back matches against outsiders Maribor to follow.
Brazilian midfielder Ramires will definitely miss the trip to Lisbon while Costa is struggling for fitness.
Mourinho, who led Porto to the 2004 Champions League before repeating the feat with Inter Milan in 2010, remains sceptical about Costa's presence in his starting line-up.
"I know for a striker scoring goals is always nice for his confidence, especially for a player like him, who is not training as he should because we are protecting him in certain situations," he said.
"If he doesn't play against Sporting he doesn't play, we can play (Didier) Drogba or (Loic) Remy." "Diego's doing almost nothing (in between matches). He's just resting and recovering from the tight muscle he has every time he accumulates fatigue." Ramires is well short of returning to full fitness and still faces at least a couple weeks on the sidelines.
"It's a muscular injury, he won't be able to play on Tuesday or even against Arsenal (next weekend), he needs the two-week international break and maybe he can be back after that," continued Mourinho.
Sporting, who conceded a 92nd minute equaliser against Maribor on matchday one, have a strong record at home against English clubs and have only been beaten once in nine fixtures.
Cristiano Ronaldo scored the only goal of the match in 2007 for Manchester United against his former club in the Champions League group phase.
Chelsea 'keeper Thibault Courtois believes his team are off to an ideal start to the season with the Belgian enjoying life as the new number one under Mourinho.
"We hope to continue like this. The season is long and you can have good moments and bad moments but we hope to stay on this line," said the former Atletico Madrid stopper.
"That will be hard but we have a good team that can do it.