Thibaut Courtois believes Cristiano Ronaldo is "irreplaceable", but he challenged his Real Madrid team-mates to score the goals the star forward used to.
Ronaldo, 33, left Madrid for Juventus in July and, while the La Liga giants struggled to cope without him initially, they have improved under Santiago Solari.
Solari secured his first trophy at the helm with a 4-1 win over Al Ain in the FIFA Club World Cup final on Sunday (AEDT).
Courtois said Madrid needed to step up to replace the goals Ronaldo scored, with Karim Benzema (11) and Gareth Bale (10) leading the way so far.
"Cristiano Ronaldo is irreplaceable, you cannot forget what he did," Courtois told reporters.
"But he is not here anymore, so it's time for other players, like Bale did in the semi-finals [of the Club World Cup], to score the goals he [Ronaldo] used to score.
"If we are able to do so, it'll be fine."
Madrid are fourth in La Liga, eight points behind leaders and rivals Barcelona, albeit with a game in hand.
They are next in action with a trip to Villarreal on January 4.