Chelsea were "improvising" tactically in the second half of their 3-3 draw with Roma according to head coach Antonio Conte, who admitted that playing David Luiz in midfield did not work.

After goals from David Luiz, Eden Hazard and Roma's Aleksandar Kolarov had made it 2-1 to Chelsea at half-time in Wednesday's Champions League clash, Edin Dzeko's superb brace put the visitors 3-2 up with 20 minutes left to play while Conte switched from a 3-5-2 formation to a 4-3-2-1.

The change seemed to work as Hazard headed the equaliser before Chelsea held out the for the final 15 minutes, although Dzeko went close to completing his hat-trick when he headed narrowly wide in the dying minutes.

"The effort the players put in was the maximum and I thank them," Conte told Mediaset Premium afterwards. "We suffered in the first half and the decision to change system didn't pay off, as it took away all our guarantees.

"We were basically improvising and it showed, as we suffered under Roma's pressing.

"We scored two goals, but the sensation was always that we didn't feel in control of the match. I have to take responsibility, as it was my decision to change the system to make up for the lack of options. I changed the David Luiz position to strengthen the midfield and I don't think it worked, to be honest."

Conte refused to blame his side's struggles during the dramatic Champions League Group C encounter on injuries.

Chelsea were without the injured N'Golo Kante, Victor Moses and Danny Drinkwater, leaving David Luiz to shore up the midfield but the Brazilian was seen struggling with a calf problem during the game.

"It's not about injuries," said Conte. "But trying to get the best out of the team. The same players have been going all the time since pre-season. We've got three injuries, not seven or eight, but it's still an emergency situation for us.

"David Luiz had a problem with his calf, [Tiemoue] Bakayoko finished with a problem in his adductor and I hope it's nothing serious.

"Despite all that, we drew with a very good Roma side and I can only praise my players. When you change system, it's all improvisation and tonight we were improvising. That is something I don't like, because I prefer organisation and to fight it out in our own way.

"I have to thank my players for their efforts, because without that, we would not have managed a point here."