Zenit St Petersburg's Aleksandr Kokorin and Krasnodar's Pavel Mamaev are said to have attacked trade ministry official Denis Pak on Monday, leaving him needing medical treatment.
The league branded them "hooligans", in what is reportedly a racially motivated outburst.
"The Russian Premier League expresses its outrage and strongly condemns their rowdy behaviour," the league said in an official statement.
"This act not only casts a shadow over the glorious names of FC Zenit and FC Krasnodar, but all of Russian football.
"We believe that those responsible should be punished in the most severe way. There is no place for hooligans in football."
Kokorin crashed a chair over trade ministry official Denis Pak, before Mamaev was filmed punching him in a car park on Monday.
Both have since been detained for questioning over the alleged racist attack and could be jailed for up to five years if convicted of racially motivated hooliganism.
Kokorin, 27, has 48 caps for the national team but missed this year's home World Cup through injury.
While Mamaev, 30, has 15 Russia caps and played for CSKA Moscow 128 times before moving to Krasnodar in 2013.
Both clubs have issued statements claiming they are seeking legal action to rescind their contracts.
"What happened yesterday in Moscow involving Aleksandr Kokorin has caused great disgust and indignation at the club," five-times Russian champions Zenit said in a statement.
"We don't think it's necessary to speak of a club punishment for the player - it will come, but right now the management of Zenit and the fans feel nothing but dismay, that one of the country's most talented footballers has behaved disgustingly.
"We await the legal assessment by the relevant bodies, but from the human and emotional viewpoint such an incident only arouses shame."