Under-fire Atletico Madrid striker Jackson Martinez has admitted that he is struggling in the early days of his spell at the Vicente Calderon.

The Colombian forward, who joined Atleti for £25m from Porto, missed a host of gilt-edged chances in Wednesday's 2-1 Champions League defeat to Benfica.

Martinez has only netted once in eight outings so far, and the 28-year-old concedes that it has been far from the dream start that he would have liked.

"Our coaching staff are doing everything to help me, but at the moment things aren't going as I'd like them to," he told reporters.

"We had the chance to score more than one goal in the first half, but we didn't take it and that allowed them to equalise.

"We sat back and gave them the chance to use the ball more, but we still had chances to score and we could have increased our advantage."

Madrid sit second in Group C, two points clear of Galatasaray and Astana, three behind the Portuguese side.