The Real Madrid assistant coach has made the club's priorities clear in terms of competitions, but insists Los Blancos will still play to win in the Spanish top flight
Priority was immediately refocused to their home encounter against Manchester United, despite Cristiano Ronaldo's hat-trick-inspired rout of the visitors at the Santiago Bernabeu.
"We have shown we still want to win every league game," Karanka told reporters after the match.
"However, the Champions League takes centre-stage now."
Ronaldo was hauled off with 20 minutes to go, preserving the Portuguese superstar's energy reserves ahead of the fixture against his former side.
"Ronaldo's fine. He works hard and has to play. He deserves it [the hat-trick]," continued defender Pepe.
"The team works hard every day. Today, we went all out. Every game is special, but on Wednesday we will have to keep [our form] up."
The centre-back was deployed as an unorthodox central midfielder on the night in the wake of Gonzalo Higuain's sending off, and he confirmed his readiness to perform the role again in midweek.
He concluded: "I'm happy to be back, and do not think playing in midfield against Manchester Uited to be an experiment."