Thomas Tuchel says Chelsea cannot ignore the fact that their performances in recent weeks have been “average”, but insists fixing the “small details” will allow them to return to winning ways, starting against Leeds on Saturday.

Chelsea have won just one of their last four matches in all competitions, and conceded three goals in their loss at West Ham on December 4 and their draw in St Petersburg against Zenit on Wednesday.

Tuchel’s side – who had conceded just 10 goals all season before those two fixtures – surrendered leads against both West Ham and Zenit, and the head coach admitted his concern before the visit of Marcelo Bielsa’s side.

“Let’s be honest, if you have the lead four times in two matches and you escape with one point and six goals conceded, it’s not the moment to look away and pretend nothing’s happening,” said Tuchel.

“I think it’s still a matter of details, still a matter of small things, and not to worry about the big picture.

“There are reasons for it, of course – we played in Zenit without any central midfielders who are used to playing there.

“The performances are not horrible, the performances are not bad. They are in some moments average, and average looks kind of horrible when you play and work for Chelsea.

“This can happen and it’s good that it feels like this because we want to compete on the highest level.

Chelsea head coach Thomas Tuchel was impressed with the strict Covid measures when his team arrived back from Russia following their 3-3 draw against Zenit St Petersburg

“I have the feeling we dropped from good performances to normal – average performances when we lead. This is very unusual for us and this should not become common.

“We’ve learned now, hopefully, twice from experience, and we have the chance to prove it now tomorrow.”

Tuchel’s midfield headache will be eased against Leeds with the news that Jorginho is ready to play through the pain of his back injury in the Premier League fixture.

Jorginho – who came third in the Ballon d’Or voting last month – missed the 3-3 draw at Zenit, but is ready to return with midfield colleagues N’Golo Kante and Mateo Kovacic still sidelined.

Kante is continuing to recover from a knee injury suffered in the 4-0 win over Juventus last month, while Kovacic remains in isolation after testing positive for Covid.

Ruben Loftus-Cheek also missed the Zenit encounter but could return to take on Leeds and should pair up with Jorginho if fit enough to feature.

“Jorginho completed the last two training sessions,” said Tuchel. “And I think he will do again what he did in the last few games he has played – play through the pain and do what’s needed to be on the pitch.”

Trevoh Chalobah remains out of action due to a hamstring injury, with Ben Chilwell a longer-term absentee due to knee ligament damage.

Reece James deputised in midfield against Zenit, with Saul Niguez trialled at left wing-back as Tuchel took a rare chance to experiment with knockout qualification secured in advance of the trip to Russia.

James will return to his more familiar role in defence against Leeds, however, with Tuchel saying: “Reecey will start as a wing-back and we will find other formations elsewhere.

“If something should happen to Jorgi, for example at the hotel before tomorrow, then we would need a solution, so we wanted to see Reece there in real life and to try Saul in a new position as well.

“But there’s no need tomorrow to try these things.”