Jose Carlos Esteves, Porto's club doctor, said that Costa, who was shown on television after the game with blood streaming from his nose, would have to have an X-ray to assess the damage. "Costa was head-butted by Weah and did not have time to defend himself," Esteves said.
Television pictures showed players from the two teams scuffling in the tunnel at the end of the game, which ended in a 1-1 draw. The match was littered with fouls and yellow cards.
Porto's coach, Antonio Oliveira, said the incident had been reported to Uefa officials present at the game, in which the Portuguese side assured themselves of finishing top of Group D. Adriano Galliani, a Milan vice- president, said he had spoken to the Porto chairman, Jorge Nuno Pinto da Costa, about the incident and said that "everything was solved". He added: "We will tell Uefa our version."
Milan are still not certain of qualification for the quarter-finals. They need a draw at home to Rosenborg Trondheim, the Norwegian champions, in their last match to ensure progress.
Atletico Madrid and Borussia Dortmund have qualified from Group B, but the outcome of Group A will be decided by the final round of games. Grasshopper Zurich, Ajax and Auxerre are all level on nine points.
The last two matches see Ajax travel to Zurich and Auxerre entertain Rangers, who on Wednesday won their first match at this level in 13 games when they beat Grasshopper 2-1. Rangers were already out of contention for a quarter-final place.
Ally McCoist yesterday told how wounded pride inspired Rangers to end their miserable run. McCoist ended his own four-year wait for a goal in the Champions' League with a 66th minute penalty and scored a second goal six minutes later. His goals earned Rangers a first victory and a pounds 500,000 Uefa win bonus after four successive defeats.
McCoist said that his team had been fired up by jibes that they were "holiday-makers" by Kubilay Turkyilmaz, the Grasshopper forward, after Rangers suffered a 3-0 defeat against the Swiss champions in Zurich in September.
McCoist said: "I just felt they rubbed it in a little bit afterwards. They accused us of a lack of professionalism. They said we were there on holiday."Reuse content