UEFA is to investigate an incident involving Marko Arnautovic as the Austria forward celebrated after scoring against North Macedonia at Euro 2020.
Arnautovic grabbed his team's final goal in the closing minutes of a 3-1 triumph in Bucharest after coming on as a substitute during Sunday's Group C clash.
Media reports said the 32-year-old directed comments at opposing players in the aftermath, with Austria captain David Alaba seemingly attempting to calm his compatriot down.
The Football Federation of Macedonia submitted an official letter to UEFA demanding the most severe punishment possible following what it described as a "nationalist outburst" towards Ezgjan Alioski, who has Albanian roots.
Arnautovic, who is of Serbian descent, issued a statement via social media on Monday to apologise for "some heated words".
Serbia does not recognise the independence of its former province Kosovo, while there is historic tension between Serbia and North Macedonia.
"There were some heated words yesterday in the emotions of the game for which I would like to apologise - especially to my friends from North Macedonia and Albania," Arnautovic posted on Instagram.
"I would like to say one thing very clearly: I am not a racist. I have friends in almost every country and I stand for diversity. Everyone who knows me is aware of that."
UEFA said on Tuesday: "In accordance with the article 31(4) of the UEFA disciplinary regulations, an ethics and disciplinary Inspector has been appointed to conduct an investigation regarding the incident involving the player Marko Arnautovic that occurred during the 2020 European Championship group-stage match between the national teams of Austria and North Macedonia on 13 June 2021."
Austria are next in action on Thursday, taking on the Netherlands - who defeated Ukraine 3-2 in their opening fixture - in Amsterdam.