The Champions League final was set to be staged at Zenit St Petersburg's stadium on May 28.
Iran became the first team to arrive in Russia for the World Cup on Tuesday, nine days before the opening match of the June 14 to July 15 tournament.
According to reports, the 57-year-old was seen being from his seat, before collapsing into a chair inside the stadium.
Russia's invasion of Ukraine was condemned by the sporting community on Thursday, with President Vladimir Putin's country losing hosting rights for the UEFA Champions League final while Formula One drivers said it was "wrong" to race there this year.
Croatia's Football Federation (HNS) sacked Ognjen Vukojevic, a member of the national team's coaching staff, over a "glory to Ukraine" video posted after Croatia beat Russia in the World Cup quarter-finals, HNS said in a statement on Monday.
"I'm very happy for my players, we showed character and the right mentality, it was very hard for us tonight. We worked hard defensively."
Images from the FIFA World Cup Round of 16 match played between Switzerland and Sweden in St Petersburg on Tuesday
With the year sprinting to a close, we bring you, in pictures, some of the best action from the sports world.
News of all that's transpired on and off the football field
Keisuke Honda announced his retirement from international football following Japan's elimination from the World Cup at the hands of Belgium on Monday night.