Gianfranco Zola has backed Maurizio Sarri's public criticism of the Chelsea players and explained it was part of a drive for consistency.

Sarri questioned his players' mentality following last Saturday's 2-0 defeat at Arsenal but they responded in fine style by overcoming Tottenham on a penalty shoot-out in Thursday's EFL Cup semi-final, second leg.

Zola, Sarri's assistant at Stamford Bridge, tried to play down the significance of the issue but admitted getting back-to-back performances from the team was key moving forward.

Speaking ahead of Sunday's FA Cup fourth-round tie with Sheffield Wednesday, he told a news conference: "I think to put too much emphasis on that would be wrong. Before we saw also very good performances.

"Obviously Thursday was one of the top ones.

"We don't question that these players can achieve peak performances, like they did yesterday. What we're trying to achieve here is we want consistency in performances, because it's the nature of the league. You can't afford to play two games well and one game less good.

"The top teams are pushing. We need to keep pace."

Much has been made of Sarri's willingness to openly criticise his players - particularly star man Eden Hazard - but Zola believes it's all part of a coach's armoury.

"It can go one or two ways, but sometimes the criticism is not necessarily a negative thing," he said.

"Sometimes as a coach, as a manager you try to always get the best out of the players. Sometimes you have to give them a compliment, sometimes you also need to criticise.

"I appreciate the players have reacted in the right way, that's the most important thing."

Hazard won the man-of-the-match award against Spurs and Zola was delighted with the Belgian's display.

"What he showed me is the reaction of a great player with great personality," he said.

"I'm looking forward to seeing him until the end of the season and for more than that. It's important that you react in that way. I was very impressed and pleased with Eden's performance."