Sevilla winger Piotr Trochowski has admitted that the injury he suffered against Barcelona could keep him on the sidelines for a lengthy spell.
Having opened the scoring, the German international limped off in the 38th minute and will now fly to Denver next Wednesday to undergo surgery and to determine the full extent of his injury.
Speaking to Sevilla FC TV, Trochowski said: "I'm not very good, I didn't expect the injury to be that serious, next Wednesday I'm sure I'll be more optimistic.
"I didn't get better and that's why we took this step and now it's known that it is more serious."
It was reported that the former Hamburg player would be out for an estimated four months but Trochowski does not want to jump to any conclusions until after his consultation.
"We can't talk about a period now, we have to talk with an expert and wait until the operation to know it."
Trochowski had enjoyed a bright start to the season and was the match-winner in Sevilla's 1-0 triumph over Real Madrid last month.