Dynamo Moscow says its players were shot at from paintball guns after practice at their training camp outside Moscow on Friday.
The culprits, dressed in camouflage, fired at players and hit a number in the head after Friday's training session.
The Russian Premier League club believes the attack was organized by fans who are angry about the club's poor start to the season which has left them lying 13th in the overall standings.
"After training exercises, a group of individuals tried to shoot the players with paintball guns," the club said in a statement on their official website.
"We are convinced this was a planned and organized action. This is a challenge to the club and we will answer in the toughest possible manner.
"We intend to use all the resources available to us to find and hold the shooters accountable in any way the current law allows, including criminal prosecution."
Dynamo's official fan club distanced themselves from the attack in the same statement.
It said: "The leadership of the Dynamo supporters' club officially announces that it has no relation whatsoever to the incident.
"In the last four games, Dynamo have earned three victories and all the thoughts of the fans are directed only to support the team.
"(Friday's events have) only strengthened our commitment to be with the players and coaches during this difficult time. We shall do our utmost to help the football club in the capture of those responsible for a criminal offense."
Information from The Associated Press was used in this report.
