Thomas Tuchel has signalled “a huge step forward” for loan signing Saul Niguez in Wednesday’s 2-0 Carabao Cup semi-final first-leg victory over Tottenham.
Chelsea were forced into a last-minute formation switch after Thiago Silva and N’Golo Kante tested positive for Covid-19.
Saul stepped up for just his seventh Chelsea start since joining the Blues on loan from Atletico Madrid in September, operating in a more familiar central midfield role in a 4-3-3 system.
And boss Tuchel was left to heap praise on the 27-year-old for finally finding his Stamford Bridge rhythm after almost four months of struggle.
“He has digested his experiences here in the beginning, when he maybe did not expect it to be like this,” said Tuchel.
“Now he would certainly not be the first player to struggle with the switch to England.
“But he’s open, fully focused and totally committed to the team.
“I’m very happy he had a performance like that, which was a huge step forward.”
Chelsea put one foot in the League Cup final with a dominant victory over fierce rivals Spurs, with Antonio Conte enduring a wretched first managerial return to Stamford Bridge.
Kai Havertz netted just five minutes in after Marcos Alonso robbed Emerson Royal deep in his own territory.
The German forward broke his finger in the process and Tuchel paid tribute to him and the other Chelsea players for dealing with the mounting injury and coronavirus-enforced absentees to put one foot in the League Cup final.
“Kai has the issue with his finger, he broke his finger and it looked horrible,” said Tuchel.
“And he played through the pain that was getting bigger and bigger. He survived until half-time and then we had to make the change.
“I liked our performance a lot. We looked full of confidence and had two late last-minute pieces of bad news with Thiago Silva and N’Golo Kante, who were both supposed to start.
“So we decided at the last minute to maybe switch to a back four. The guys were very committed and very open to that, to making such a late change.
“And it was a very strong performance, so it was a well-deserved win in a big match against a very strong opponent.”
Ben Davies then put through his own net, unwittingly deflecting the ball off his shoulder from Davinson Sanchez’s botched clearing header.
Chelsea suffocated sloppy Spurs but also spurned several fine chances that if converted would have killed the semi-final tie at the midway point.
Saul finally showed his true pedigree with a tenacious and measured midfield performance.
And Chelsea’s German coach Tuchel admitted he has seen Saul start to improve day by day now he has warmed to his west London task.
“He’s more happy, more free in training; I see it every day,” said Tuchel.
“He played better when he came on against Wolverhampton.
“He’s stepping up and stepping up.
“I was so happy when I saw him on the sideline when we scored the equaliser against Liverpool. He was totally involved in the moment, totally committed.”