The Blues only had 40 per cent possession but found themselves 2-0 up after 37 minutes through David Luiz and Eden Hazard.

Roma fought their way back before Hazard saved Conte's blushes with a late header, and Conte believes the players struggled in a different system.

He said: "It was fair. It was a difficult game against a good team. Above all in the first half we suffered, our performance was good but for sure our football is different than today.

"We suffered possession and it wasn't easy in the first half, despite scoring two goals. The change of the system wasn't good, but when you are in a difficult situation you have to change and sometimes to improvise.

"When we changed in the second half the situation was changing. David Luiz had a little problem in his calf and in this moment I can't risk my players. we are playing always the same players."

Conte tweaked his usual formation and operated with David Luiz at the heart of a three-man central midfield.

Chelsea were without N'Golo Kante and Victor Moses but were boosted by the return of Spanish striker Alvaro Morata, who linked up well with goalscorer Hazard.

They were looking to bounce back from consecutive Premier League defeats but a draw keeps them top of Group C following Atletico Madrid's 0-0 draw at Qarabag.

Conte's side travel to Rome in a fortnight for the return leg.

They return to Premier League action this weekend as they host high-flying Watford at Stamford Bridge.