Glen Kamara could face a five-match ban after UEFA opened disciplinary proceedings against the Rangers midfielder and the Slavia Prague player he accused of racism.
Kamara has been accused of "serious assault" after European football's governing body investigated claims made by both parties in the aftermath of the Czech leaders' Europa League win at Ibrox on March 18.
Slavia filed a criminal complaint against Kamara the following day after alleging he punched Ondrej Kudela.
Kudela faces a minimum 10-game ban if found guilty of insulting the "human dignity" of Kamara on the grounds of his skin colour and race.
The 34-year-old also faces a lesser charge of insulting Kamara, having claimed he called the Rangers player a "f****** guy" rather then the racial slur which Kamara and team-mate Bongani Zungu reported hearing.
Having effectively admitted the lesser charge, the Czech international has been handed a provisional one-match ban by UEFA's control, ethics and disciplinary body (CEDB) "without prejudice" to any ruling the body might make on the racism allegations.
Slavia had earlier announced the defender would not be travelling to London for their quarter-final first leg against Arsenal because of illness and a facial injury caused when he was caught in the nose by the elbow of Wales midfielder Gareth Bale.
Slavia have reported the UEFA inspector as declaring that "in the absence of compelling evidence to determine the content of the remark made by Mr Kudela", the official was "not in a position to confirm or contradict" Kamara or Zungu's account.
A decision will be taken by UEFA's CEDB "in due course".
UEFA's initial response has been criticised by Kamara's lawyer, Aamer Anwar, who called for Kudela to be banned for at least a year on the basis of the evidence the European governing body had received.
Anwar added in a statement: "Kudela will not be allowed to play the Europa League match against Arsenal, which also means that Police Scotland will not be able to question him on Thursday with regards to their criminal investigation against him.
"I understand that Police Scotland have a sufficiency of evidence to proceed with charges against Kudela, without the need to speak to him.
"Whilst UEFA have carried out an initial investigation which makes damning reading about Kudela's conduct, this initial one-match ban does little to instil confidence in UEFA being serious about stamping out racism in football and they must take robust action going forward.
"The defence put forward by Slavia Prague can only be described as incredible or fantasy.
"A one-match ban will make no difference whatsoever to Kudela or Slavia Prague, who were already claiming he was too ill to travel to Arsenal. A one-game suspension smacks of 'tokenism' and gives little confidence to black players who face such vile abuse.
"The overwhelming evidence against Kudela means UEFA must take immediate action to punish him robustly for the crime he is accused of."
A Slavia statement read: "In view of the pending UEFA disciplinary proceedings as well as the police's investigation we will not provide further comments on the matter."