rtokens: He has offered to apologise if Costa acknowledges the provocation .
pos: NNP VBZ VBN NN VBG NNP CC VBD PRP VBD TO JJ NNS .
tokens: Weah has admitted head butting Costa but said he reacted to racist taunts .
ltokens: The incident took place in the players ' tunnel after a European Champions ' League match on November 20 .