After one dangerous hit too many, the league apparently has seen enough.

The NFL suspended Harrison for one game following his helmet-to-facemask hit on Browns quarterback Colt McCoy last Thursday, making Harrison the first player to miss game time as a penalty under the league’s revamped policy on such collisions.

Harrison’s agent Bill Parise said yesterday Harrison has already filed an appeal and expects it to be heard later this week by Art Shell or Ted Cottrell.

They’ll have to determine Harrison’s intent when he laid out McCoy late in the fourth quarter of Pittsburgh’s 14-3 victory. The 2008 NFL Defensive Player of the Year was penalized for roughing the passer on the play and said Monday he believed the hit didn’t warrant further punishment.

NFL executive vice president Ray Anderson disagreed, pointing out the violation marked the fifth illegal hit on a quarterback by Harrison in the last three seasons. The four-time Pro Bowler has also been fined on two other occasions for unnecessary roughness over the same period.

Harrison, who has been highly critical of the league’s crackdown on vicious hits, thanked his fans for their support on his Twitter account after the suspension was levied, adding, “I’m just going to move on from here and get ready for my next game.’’

Barring a successful appeal, that won’t be until the Steelers (10-3) face St. Louis on Christmas Eve.

The Steelers pledged to press onward even if it means being without their All-Pro linebacker for Monday night’s game at San Francisco.

“We’re disappointed for James because we know how hard he’s worked to play within the rules,’’ coach Mike Tomlin said. “We accept the judgment rendered by the league office and we’ll move forward.’’

Meanwhile, an investigation by the NFL and Players Association into the Browns’ handling of McCoy’s concussion could lead to changes in the league’s medical procedures and protocol on head injuries. League and NFLPA representatives met with the Browns yesterday to discuss McCoy’s injury, which may have exposed some previously unaddressed issues tied to the concussion policies.

The Browns said McCoy, whose head snapped back after he was struck on the facemask, did not show symptoms of a concussion until after the game. Coach Pat Shurmur claims the team followed medical protocol before McCoy was allowed to return just minutes after absorbing the vicious hit.

The NFLPA could file a grievance on McCoy’s behalf if it’s determined the Browns did not test him properly for a concussion. The league could also take action against the club.

Roethlisberger ailing

Steelers quarterback Ben Roethlisberger is questionable for Monday night’s game at San Francisco because of a sprained left ankle. Roethlisberger was hurt in last week’s win over Cleveland in the second quarter after turning the ankle. He returned to throw for 178 yards and a touchdown in the second half . . . The Cowboys put rookie running back DeMarco Murray (ankle) and safety Barry Church (shoulder) on season-ending injured reserve and signed veterans Sammy Morris and Mana Silva as replacements. Murray, who had a franchise-record 253-yard game in October, finished with 897 yards and two TDs. Morris, a 12-year veteran, was released by the Patriots in the preseason. He will back up Felix Jones.

Leonard hopes to return

Jim Leonhard hopes he has not played his last game with the Jets. The injured safety said in a radio interview that he will have surgery to repair the torn patellar tendon in his right knee this morning and hopes to return to the team. Leonard, 29, is a free agent after this year, but has had season-ending injuries the last two years. The Jets signed veteran safety Gerald Alexander, who was waived by Miami last month, to shore up the position . . . The Titans signed linebacker Kevin Malast off the Jaguars’ practice squad and placed veteran linebacker Barrett Ruud on injured reserve . . . The Panthers signed rookie kicker Adi Kunalic, but will keep veteran Olindo Mare on the roster. Mare missed a 36-yard field goal with 5:26 left in Sunday’s 31-23 loss to the Falcons.

Pioli accepts blame

General manager Scott Pioli pointed his finger at himself when asked to explain the Chiefs’ disappointing 5-8 season. “We have a locker room that has talent. We also have a good makeup of character in that locker room,’’ Pioli said, “but it’s abundantly clear that we’re not in a spot we need to be with our record where it is and our team in a position it is. I need to do a better job.’’ The Chiefs’ 37-10 loss to the Jets Sunday culminated in the decision to fire coach Todd Haley, once a rising star in the NFL, and the appointment of defensive coordinator Romeo Crennel as interim coach for the final three games . . . A number of key Dolphin players expressed their surprise that coach Tony Sparano was fired with only three games remaining in the season. “It’s a shame he had to go out that way,’’ said quarterback Chad Henne. “I wish I could have him for another year as my head coach because I respect the hell out of him.’’ Todd Bowles, the Dolphins’ assistant head coach/secondary, has been elevated to interim head coach.