Kostas Manolas should be fit to return to the central defence alongside Federico Fazio, fresh from signing a contract extension, who has impressed since replacing the Greek against Napoli two weeks ago and been key in the subsequent three straight clean sheets in the league (admittedly against middling and outright poor opposition).
"In London, we saw a handsome Roma and tomorrow I want to see the same mentality", said boss Eusebio di Francesco.
The hosts got off to a dream start when a cross into the area glanced off Edin Dzeko's shoulder and bounced right to an onrushing El Shaarawy, who blasted a right-footed shot past Thibaut Courtois for the early lead.
Chelsea: Courtois, Azpilicueta, David Luiz, Rudiger, Zappacosta, Drinkwater, Cesc Fabregas, Bakayoko, Alonso, Morata and star player Eden Hazard. In a unsafe attempt at playing out from the back Aleksandar Kolarov passed straight to the feet of the Chelsea striker who somehow blazed a shot over the crossbar from five yards out. Roma are in a good moment of form.
Marcos Alonso cut in from the left and forced Alisson to push a rasping shot behind, while Bakayoko compounded Chelsea's woes by powering a header wastefully wide from the resulting corner.
"The most important thing is to go game by game, tomorrow is the most important game". The onslaught of pacey attacks proved too much for Chelsea and eventually Diego Perotti put the game out of sight for the home side, who played with incredibly confidence and flair.
El Shaarawy's first goal came after only 40 seconds for Roma's fastest ever goal in Europe.
"A defeat at Roma though, combined with an expected Atletico home win against Azerbaijan champions Qarabag, will make the group a three-horse race again".
"Our group is a tough group with Atletico Madrid and Roma, two really group teams". Knockout football is far less forgiving and a loss such as this will not serve Chelsea well should they make it any significant distance into the competition.