WASHINGTON — Washington Capitals forward Tom Wilson was banned 20 games by the NHL on Wednesday for a blindside hit to the head of an opponent during a preseason game, the latest and most severe punishment in what the league called an “unprecedented” series of suspensions for the physical player.

Wilson’s fourth ban in less than 13 months will cost him nearly a quarter of the 82-game regular season — only five NHL players have been suspended longer for on-ice play — and $1.26 million in salary. It was announced just hours before the reigning Stanley Cup champion Capitals were to raise a banner and open their title defense by hosting the Boston Bruins.

The right winger, who plays on Washington’s top line with captain Alex Ovechkin, was ejected for the hit on St. Louis Blues center Oskar Sundqvist in the second period of the teams’ exhibition game on Sunday. Wilson had an in-person hearing with the NHL’s Department of Player Safety in New York on Wednesday.

The video released to explain the punishment says: “Wilson delivers a high, forceful hit, which makes Sundqvist’s head the main point of contact.”

Blues coach Mike Yeo called the hit “predatory.”

Wilson’s suspension is the longest handed down by the league since Raffi Torres of the San Jose Sharks was banned a record 41 games in 2015, also for a preseason hit.

The league noted that Wilson “is considered a repeat offender.”