Chelsea delivered what felt like a major statement under Enzo Maresca at Stamford Bridge on Tuesday. Jules Kounde's early own goal set the tone before Estevao and Liam Delap struck to secure a comfortable victory over a Barcelona side reduced to ten men when Ronald Araujo was dismissed.
Estevao's moment of brilliance would normally have secured him the man-of-the-match award, but Cucurella walked away with the honour after shutting down Lamine Yamal, a feat few full-backs have managed since the teenager's rapid rise.
Wayne Rooney, speaking in his role as a pundit, said it was the best display he had seen from a left-back "for a long, long time", while goalkeeper Robert Sanchez claimed Cucurella "had Yamal in his pocket".
Fernandez said the Chelsea squad fully appreciate what Cucurella brings to the team.
"Obviously Marc is a beast," the Argentina midfielder said. "He is very funny, always in a good mood, and he trains very well. He always wants to improve and it is very important for us to have a defender of his quality."
Fernandez also praised Chelsea's maturity on the Champions League stage and pointed to Barcelona's risky approach.
"We were delighted with the result," he said. "We showed our character and we felt more comfortable as the match went on. After Araujo's sending off, Barcelona had to be compact, which gave us more space.
"Their defensive line was very high. We knew the spaces were in behind and the manager prepared us for that. We improved during the match and a 3-0 win is an excellent result."
Despite the impressive display, Fernandez has insisted Chelsea are not getting carried away.
"We are taking it step by step," he added. "We do not put ourselves in the position of a contender, even if we represent a very big club. We have a great team and we are moving forward one step at a time."
Chelsea return to Premier League action on Sunday when they host early leaders Arsenal at Stamford Bridge, where Cucurella's form will again be crucial.
Diego Simeone has urged his Atletico Madrid players to embrace the challenge of facing Barcelona on Tuesday night, after offering sympathy to Hansi Flick following the Barcelona manager's emotional moment with Raphinha at the weekend.
Wojciech Szczesny has admitted he "had enough of this suffering" after years of battling the lingering effects of the double-arm fracture that changed his career, with the Barcelona goalkeeper revealing how the pain still affects him today.
Barcelona were preparing to unleash Raphinha, Lamine Yamal and Robert Lewandowski from the start as Hansi Flick planned a decisive reshuffle for this afternoon's clash with Deportivo Alaves.
Mikel Arteta insists Declan Rice has yet to reach his ceiling as Arsenal prepare for Sunday's heavyweight clash with Chelsea.
