Atletico Madrid coach Diego Simeone and captain Koke backed striker Julian Alvarez on Wednesday despite a poor run of form ahead of the Spanish Super cup semifinal derby clash against Real Madrid.
Argentina international Alvarez, a key player for the Rojiblancos, has scored just twice in his last 10 games across all competitions.
Atletico take on city rivals Real in Jeddah, Saudi Arabia on Thursday, bidding for a place in Sunday's final.
"The big players all demand a lot from themselves, obviously we don't have to demand a lot only from Julian but from all of us, to achieve the objectives that we want," Koke told a news conference.
"Big players like Julian appear when you need them most, tomorrow is an important day."
Koke recalled Alvarez's superb display in the 5-2 win over Real in September, in which the forward netted twice.
"I hope he has the luck, like he did in the previous game at the Metropolitano, where he had an incredible game," continued Koke.
"I'm certain that when we need him most, he will be at 100 per cent."
Alvarez joined Atletico in August 2024 from Manchester City, for an initial 75 million euros ($88 million).
The 25-year-old has netted 11 times in 24 matches this season, seven of those in LaLiga, where Atletico are fourth, seven points behind second-place Real.
Simeone said earlier this season that Alvarez was the team's most important player and called on the striker to remind everyone of his quality.
"Julian has showed the player that he is (but) sometimes words aren't enough, only deeds will do, and we hope tomorrow he has a great game," added Simeone.