The NHL's Department of Player Safety announced the decision on Friday, following a hearing.
Under the terms of the collective bargaining agreement, Fiala will forfeit $77,586.21, an amount based off his average annual salary. The money goes to the Players' Emergency Assistance Fund.
Fiala was assessed a major and game misconduct for the play, which occurred in the second period. It caused him to miss the remainder of the 5-3 win. Roy was slow to get up and was helped off the ice by teammates Jeff Carter and Anze Kopitar. Roy was able to fly home with the team.
"It will be on multiple videos, teaching clips for young players, older players, junior players, pro players on basically what not to do," Kings coach Todd McLellan said after the game. "I feel bad for Roysie. I don't even know if there's any intent on the Fiala thing; it just happened. But we have to know by now that we can't do that."
Fiala does not have a prior history of suspensions. The 24-year-old scored a goal earlier in Thursday's game.