A match penalty is called on players who purposely injure opposing players. It calls for the offending player to immediately leave the game and head to the locker rooms. A substitute player must come on the ice in his place to serve five minutes in the penalty box.
The offending team will be short-handed, or down a player for 5-on-4 during this time. The other team is on a power play. Once the penalty clock expires, the player can return to the ice to bring his team to full strength. Match penalties are like major penalties in that they are served in full even if a goal is scored.
On a match penalty, the offending player cannot return to the game. It's a very serious penalty. Goalkeepers can never sit in the penalty box.
If a goal is made on a power play while a match penalty is being served, the penalty clock will immediately expire and the offending player may return to the ice. The offending team returns to full-strength.