LONDON: Chelsea manager Thomas Tuchel said on Friday that his team are far from being a finished product although they are a tougher side for opponents to play against since he took charge.

Chelsea are unbeaten in eight matches in all competitions since Tuchel replaced club great Frank Lampard last month after the German guided them to a 1-0 win over Atletico Madrid in the Champions League last-16 first leg on Tuesday.

Tuchel has focused on shoring up Chelsea's defence in his efforts to make them more consistent and the London side have conceded only two goals in their last eight games.

"I think it's not a pleasure to play against us but the picture isn't finished. We have a long way to go," he told a news conference ahead of Sunday's Premier League clash at home to Manchester United.

"There's no other way to stay hungry, improve every day... there's lots to improve. I can clearly feel the energy of my team. We're a strong group, have strong competitors and that makes us hard to beat. Football is a team effort."

Tuchel said he is well aware of the challenge posed by United, who sit six points and three spots above his fifth-placed team and are unbeaten away this season.

"Hopefully we win, we know this is a big challenge," Tuchel added. "They have individual quality, can hurt you with speed, they're a strong team away from home, they defend very compact, are very good in transitions."

Tuchel hailed striker Olivier Giroud, who scored the winner against Atletico, but did not disclose if the Frenchman would start against United. Injured defender Thiago Silva misses out.