FC Porto's Brazilian striker Derlei could miss the UEFA Super Cup against Valencia CF next week.
The 29-year-old Brazilian was injured on Sunday night during a friendly with city rivals Boavista FC. It is not yet known how long he will be out for. This is the latest setback for a player who sat out five months of last season with a serious knee problem before returning to play a pivotal role as Porto won the UEFA Champions League.
Initial estimates suggest Derlei will be absent for at least three to four weeks, starting with the Portuguese Super Cup this Friday when the domestic champions kick off their campaign against cup holders SL Benfica. He will hope to be back for the start of the Champions League group stage on 14/15 September.
Derlei, who appeared in last year's Super Cup when Porto lost 1-0 to AC Milan, scored the decisive penalty in the Champions League semi-final second-leg victory against RC Deportivo La Coruña. As European champions, Porto will meet UEFA Cup winners Valencia CF in the Super Cup on Friday 27 August in Monaco.