Atletico Madrid coach Diego Simeone backed Jackson Martinez to find goalscoring form after his side were beaten 1-0 by Villarreal.
A 14th-minute Leo Baptistao goal was all Villarreal needed to secure their victory on Saturday, moving top of La Liga by a point.
Martinez, who joined Atletico in July, has only one goal in six league games for the club and he was substituted at half-time.
Simeone said he was confident the Colombia international would find the form that made him so prolific at Porto.
"Jackson is a very important player for us," he said.
"We blindly trust him and expect him to appear in the important and decisive moments."
Simeone said his team simply did not do enough in the second half, despite pushing for an equaliser at El Madrigal.
"The match was fairly clear. We knew from earlier matches that Villarreal is an ordered, worked team and that the details would decide the match," he said.
"They took advantage of the situation in the first half. We pushed in the second half, but couldn't do it."
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.