Russia on Wednesday announced that foreign athletes may not exceed 25 percent of a professional sports club's workforce.
The Russian health and social development ministry's quota comes into force on April 29, and applies to every team from football's Russian Premier League to hockey's KHL to basketball's VTB League.
The decree was published in the government's newspaper, Rossiiskaya Gazeta, on Wednesday.
"Foreign athletes in Russian teams must be no greater than 25 percent of the overall number of employees, including masseurs, chefs, admin and other technical personnel," the newspaper said.
"This rule applies to all categories, from regional teams to the highest leagues."
The budgets of football, basketball and volleyball teams are "eaten up" by foreign coaches and players, the newspaper said.
The rule does not appear to threaten the make-up of most of Russia's top clubs, which tend to employ many more Russians than foreigners
The quota found support in the All-Russian Volleyball Federation, whose chief said it was critical not to impede the development of young talent.
"I support the new regulations," said Stanislav Shevchenko.
"In my opinion, Russian athletes should play in our teams, and the foreigners who play should be of the top level only. Our organization already maintains the foreigner quota at an even lower level than 25 percent, though many insist on its expansion."
In football, the ministry decree will act alongside existing regulations that limit the number of foreigners on the field of play at one time to five.
From next season, even those players with Russian passports will still be considered foreigners if they have ever played for the national team of any other country.
