Cesar Azpilicueta has urged Chelsea to atone for falling off the top of the Premier League and finishing second in their Champions League group.
The European champions twice surrendered the lead in Russia on Wednesday night to draw 3-3 with Zenit and end the Group H campaign as runners-up.
Thomas Tuchel’s Blues could now face Real Madrid or Paris St Germain in the last 16.
And, having slipped off the top of the league table thanks to Saturday’s 3-2 loss at West Ham, the captain has demanded an immediate response.
“We wanted to finish top of the group but we’re having a tough moment in the last couple of games where the performances haven’t been very good, and the results are reflective of that,” Azpilicueta said.
“We have to have a reaction. We know there is still a lot to play for but we lost top spot in the Premier League and top spot in our Champions League group.
“So we have to face the reality and analyse ourselves.
“We are not at our top level and we have to have a reaction.
“We have to start building our confidence because at the moment it’s true, we’re making a lot of mistakes.”
Chelsea will hope their midfield injury glut can abate in time for Saturday’s Premier League clash with Leeds at Stamford Bridge.
Ruben Loftus-Cheek was added to that casualty list, pulling up with a minor issue in the warm-up in St Petersburg.
N’Golo Kante remains out with knee trouble, Mateo Kovacic is isolating after testing positive for Covid-19 and Jorginho has a back niggle.
Tuchel will hope that Loftus-Cheek and Jorginho could be ready to take on Leeds, to ease the strain on his squad.
Chelsea briefly topped the Premier League table last December, only to drop as low as ninth before Frank Lampard was sacked in January.
Azpilicueta knows how quickly positive situations can change, but asked if there were any similarities now with last December, he replied: “No. It is true that in Chelsea you don’t need a big number of defeats in a row to call it a bad period or a crisis.
“It is part of this club’s ambition to go into every competition with the ambition to compete at the top.
“Last season in December we were top of the group in the Champions League and top of the Premier League and we had a very bad run of results.
“But every year is different. We have different people, different players and it is just that we need everybody to get that extra per cent as individuals and as a team.”