Gianfranco Zola admits he expected more from Chelsea captain Gary Cahill and Andreas Christensen against Derby as the pair struggled defensively in the 3-2 win at Stamford Bridge.
Cahill and Christensen were both handed a start for Chelsea's EFL Cup fourth-round tie against Frank Lampard's team, but both made a number of errors during the narrow victory.
Cahill, who is out of contract next summer, was at fault for Derby's first equaliser as he conceded possession to Tom Huddleston, which allowed the midfielder to set up Jack Marriott for his fine finish in the ninth minute.
Despite the mistake, Maurizio Sarri left Cahill on for the entirety of the match but brought off Christensen for first-choice centre-back David Luiz in the second half with Chelsea winning 3-2.
In Pictures | EFL Cup | 31/10/2018
Zola, who gave the post-match press conference to reporters instead of Sarri, admitted that Cahill and Christensen's distribution of the ball, in particular, was an issue and conceded that a lack of game time could have contributed to their shaky performances.
"A player like Cahill, they play and then they don't for a while, so they might have a problem," Zola told reporters on Wednesday.
"I didn't mean the defenders didn't defend well. Everyone has to participate in the defensive phase. Some things didn't work.
"I thought Gary and Christensen could have done better in the first half. Normally their distribution is better than tonight. That's the complaint. But we'll go through this."
