Emerson starts at left-back while Olivier Giroud will lead the attack with Eden Hazard back out wide.
The bench includes Willian, Callum Hudson-Odoi and, for the first time this season, Lucas Piazon.
Tottenham start with Fernando Llorente up front. Moussa Sissoko is fit after injury, and there are changes at full-back from the first leg with Serge Aurier and Ben Davies coming in.
Gonzalo Higuain, who has signed on loan for the remainder of the season, is ineligible to feature tonight but will be presented to the crowd 15 minutes prior to kick-off.
Chelsea: Kepa; Azpilicueta (c), Rudiger, David Luiz, Emerson; Kante, Jorginho, Barkley; Pedro, Giroud, Hazard.
Subs: Caballero, Alonso, Ampadu, Kovacic, Piazon, Willian, Hudson-Odoi.
Tottenham: Gazzaniga, Aurier, Alderweireld, Vertonghen (c), Davies, Sissoko, Dier, Winks, Eriksen, Lamela, Llorente.
Subs: Lloris, Rose, Sanchez, Walker-Peters, Skipp, Moura, N’Koudou.
Referee: Martin Atkinson.
This is our 23rd major semi-final since the arrival of Roman Abramovich in 2003.
Maurizio Sarri’s side have won 13 and drawn four of our 18 home games this season. Our only defeat was against Leicester before Christmas.
Eden Hazard was fouled on seven occasions against Spurs in the first leg two weeks ago; the most fouls he has suffered in a game this season. All three of Tottenham’s yellow cards were given for fouls on him.
Marcos Alonso’s strike against the post at Arsenal was his sixth effort against the woodwork this season, more than any other Blues player. In all we have struck the frame of the goal on 21 occasions in our 35 games this term, compared to eight from our opposition.