John Mikel Obi and Victor Moses have left to compete in the Africa Cup of Nations, while John Terry (knee) and Oriol Romeu (knee) remain injured.
Swansea's only absentee is Neil Taylor, who has been ruled out for the season with a fractured ankle.
Gerhard Tremmel is set to start in goal, and Angel Rangel is available after a calf problem.
Never mind that the League Cup isn't seen as the most glamorous of garlands - both managers will be hugely motivated to ensure their team reaches next month's final at Wembley, and for wildly different reasons.
Michael Laudrup's status as Swansea boss is rock solid at the moment: he is as cherished as water in the desert for guiding the south Wales club to an unprecedented semi-final in this competition, and for working wonders in the pressure-cooker Premier League.
But the urbane Dane is still desperate to guide the Swans to a first major trophy in the club's 100-year history, which would seem a distinct possibility should they overcome Chelsea, who are the reigning European champions lest we forget.
The Blues don't want for silverware, especially in the modern era, but for Rafa Benitez it's all about his reputation - in the eyes of sceptical Stamford Bridge supporters, and also in the eyes of critics who question whether he can ever repeat the miracles he once produced at Liverpool.
Both teams are in good shape going into the game. Swansea's squad are proving they have the depth to cope with a congested fixture list - so far - while Chelsea are going from strength to strength as an attacking force, especially with the addition of prolific striker Demba Ba from Newcastle.
Over two tension-filled legs, it should be quite a tussle.
MATCH FACTS
- The two clubs have only met once on the League Cup, when Chelsea beat Swansea 3-2 at Stamford Bridge in the fourth round of the competition in November 1964.
- Swansea have only once beaten Chelsea at Stamford Bridge (in any competition), a 3-1 Division Two victory when the clubs first ever met back in November 1925.
- The last two matches between the clubs have ended in a 1-1 draw (both in the Premier League at the Liberty Stadium).
- They last reached the League Cup semi-finals in 2008, when they beat Everton to reach the final - only to lose to Tottenham.
- The Blues won the League Cup for the fourth time a year earlier, in 2007. Only Liverpool (eight) and Aston Villa (five) have won the competition more often.
- Chelsea have scored a total of 16 goals in eliminating Wolves, Manchester United and Leeds in their previous League Cup ties this season.
WYMB!