The Associated Press

NEW YORK — The NFL imposed huge fines Tuesday on three players for dangerous and flagrant hits last weekend and warned that, starting with this week’s games, violent conduct will be cause for suspension.

Pittsburgh Steelers linebacker James Harrison was docked $75,000 on Tuesday, while New England Patriots safety Brandon Meriweather and Atlanta Falcons cornerback Dunta Robinson will lose $50,000 each.

In the past, players were either fined or ejected for illegal hits. However, after the series of recent flagrant tackles, several of which resulted in concussions, the NFL ramped up the punishment.

Football operations chief Ray Anderson indicated the suspensions could start immediately — that is, involving play from last weekend’s games. However, NFL spokesman Greg Aiello said the league wanted to give teams fair warning and would send a memo Wednesday, outlining the changes.

Ravens tight end Todd Heap took a vicious hit from Meriweather that Heap called “one of those hits that shouldn’t happen.” Robinson and the Eagles’ DeSean Jackson were knocked out of their game after a frightening collision in which Robinson launched himself head first to make a tackle. Both sustained concussions.

Harrison was punished for his hit on Mohamed Massaquoi. His hit on Joshua Cribbs did not figure in the fine, although it also caused a concussion; the league said Monday it was permissible.

Harrison’s agent, Bill Parise, called the fine “staggering” and said it would be appealed. He emphasized that neither play drew a penalty.

“I’ve talked to James, and he’s very upset,” Parise said. “He’s quite confused about how to play football.”

The league noted Harrison is a repeat offender; he was fined $5,000 for unnecessary roughness in Pittsburgh’s win over Tennessee on Sept. 19.