The ongoing political situation in Crimea is already impacting the region's two football teams.
Teams will finish the Ukrainian season, but could find themselves in the Russian Premier League by the end of the year.
Some political figures are also questioning Russia's hosting of the 2018 World Cup.
Basketball and handball teams from Crimea have already stopped playing in Ukrainian leagues.
Russian President Vladimir Putin signed into law a treaty on Friday, formally making Crimea part of the Russian Federation.
Al Jazeera's Elise Holman reports.
