The players are not under investigation for any criminal charges, a person with knowledge of the discipline told The Associated Press on Monday.
A university statement, citing educational data privacy, said Monday that additional information on the punishment will not be shared "at this time."
Coach Richard Pitino said on his weekly radio show on 1500 ESPN that he "anticipated" all three players will be available to play against rival Wisconsin on Wednesday. Pitino declined to comment specifically on the reason for the suspensions.
"Today was unfortunately not as much about wins and losses but more about the culture of our program," Pitino said after the 84-71 loss to the Illini. "It was about making sure our guys understand that this thing is bigger than just basketball, and we're going to do what we believe is right."
In a statement issued by the team prior to tipoff, Pitino said of the three players, "With the privilege of being a member of the University of Minnesota basketball program there are expectations and standards to which we hold our student-athletes accountable, and they have failed to do so."
The Gophers played the game with only six scholarship players. Walk-on freshman Stephon Sharp started at point guard, and only seven players appeared on the court. Dorsey, Mason and McBrayer traveled with the team to Illinois but sat on the bench in street clothes.
Mason, a sophomore, leads the Gophers (8-20, 2-14 Big Ten) with averages of 13.8 points and 32.6 minutes per game. Dorsey and McBrayer are freshmen, both among the top eight players on the team in terms of time on the court.
Information from The Associated Press was used in this report.