Uefa has charged PSV Eindhoven defender Eric Addo with gross unsporting conduct after he spat on Fenerbahce player Semih Senturk during the UEFA Champions League clash on Tuesday.
In a brief statement, Uefa said that the case would be dealt with on Friday.
A Uefa spokesman said: "Addo is alleged to have spat at an opposition player in the first half of the match."
The PSV man faces a minimum one-match ban if found guilty, although he could be banned for longer.
According to the Dutch club's official website, the Ghana defender has already apologised to his manager Ronald Koeman and PSV general director Jan Reker.
Reker said: "PSV cannot accept this kind of behaviour on the field.
"Eric has admitted he allowed himself to be provoked and has apologised.
"One thing must be crystal clear - spitting does not belong on a football field."
PSV claim that Addo was provoked by Senturk just before the spitting incident, as the Turkish player 'clearly elbowed him'.
The match at the Philips Stadion in Eindhoven finished in a 0-0 draw.