Sporting Lisbon v Chelsea: Hosts protecting fearsome home record
It will not be an easy assignment for the Premier League pacesetters, with Sporting defending a 16-game unbeaten run in European fixtures on home turf, while they have only lost once in their last nine games to English visitors.
Jose Mourinho returns to a club he served as assistant manager to Sir Bobby Robson in the early 1990s but there will be no warm welcome for the former Porto and Benfica manager who will look to get his side's campaign on track when the two teams meet on Tuesday.
The 2012 winners were in control of their opening Champions League encounter at home to Schalke, leading through Cesc Fabregas' first for the club. But they were denied all three points by a second-half Klaas-Jan Huntelaar strike and will want maximum points in Lisbon.
Mourinho's men go into the game high on confidence after beating Aston Villa 3-0 at the weekend to maintain their position at the top of the Premier League.
The win over Villa saw Diego Costa score his eighth for the club since his summer move from Atletico Madrid but Mourinho admitted afterwards that the striker is doing little training during the week as he seeks to find full fitness after hamstring trouble.
Costa was only able to make a brief cameo appearance in the Schalke draw, with Didier Drogba unable to fully replace the red-hot Spaniard's presence up front, and Loic Remy could be a more likely starter in Portugal if the former Atletico Madrid man requires resting again.
Brazilian midfielder Ramires is ruled out and is not expected to feature until after next month's international break.
Like Chelsea, Sporting go into the game having surrendered a winning position in their first Champions League game since 2009.
On-loan Manchester United winger Nani put Marco Silva's side ahead with 10 minutes to go against Maribor but were pegged back by an injury-time Luka Zahovic strike.
The 2013-14 Primeira Liga runners-up have had a slow start to the season. Although undefeated, Sporting find themselves six points behind leaders Benfica having drawn four of their six league games.
Their last game ended in a 1-1 draw against Porto. Jonathan Silva put Sporting ahead in the second minute but a Mouhamadou-Naby Sarr own goal in the second half ensured the spoils were shared.