For the past three years, I honestly believed oft-suspended NHL forward Matt Cooke was a changed man.

Thirty-six months after receiving a season-ending suspension for elbowing New York Rangers defenseman Ryan McDonagh in the head, Cooke seemed to clean up his act. A player with a history of dirty play and five suspensions on his resume, Cooke earned plaudits for subsequently abandoning his dangerous style, becoming an effective checking line forward.

Ottawa Senators owner Eugen Melnyk’s claims last season that Cooke’s accidentally cutting Senators defenseman Erik Karlsson’s Achilles tendon with his skate was a deliberate attempt to injure were roundly, and rightly, rejected. I was among those who defended Cooke and my opinion hasn’t changed that it was an accident. For me, Cooke had successfully changed his ways. I gave him the benefit of the doubt.

Dirty players like Matt Cooke have no place in the NHL.

Dirty players like Matt Cooke have no place in the NHL.

And then came his deliberate knee-on-knee hit on Colorado Avalanche defenseman Tyson Barrie this past week. In that instant, Cooke erased nearly three years of accrued good will, earning a seven-game suspension.

Following his suspension for kneeing Barrie, Cooke claimed it wasn’t his intent to injure the Avs defenseman and was merely trying to finish his check. He blamed it on the intensity of playoff hockey, reminding everyone he’s been a changed man since the McDonagh hit.

Bullshit.

His actions over the past year prove otherwise. There was his boarding of Boston’s Adam McQuaid in last year’s playoffs,  kneeing Dallas’s Valeri Nichushkin in March, followed by a late hit on Edmonton’s Sam Gagner.

As ESPN.com’s Pierre LeBrun observed, the Barrie suspension is the sixth of Cooke’s career, for a total of 34 games, plus he’s been fined four times.

Cooke’s dirty hit on Barrie wasn’t an accident or a slip-up, but a move consistent with his style of play for most of his career. Fines and suspensions did nothing to change his ways.

Sorry, “Cookie Monster” (as some pundits and fans call him), but I ain’t buyin’ it. For whatever reason, you just can’t help yourself from deliberately attempting to injure opponents.

Thanks to Cooke’s actions, Barrie’s season is likely done. He’s out between four-to-six weeks with a knee injury. The best that can be said is he didn’t suffer a worse fate. I’m referring, of course, to Cooke’s blindside head shot on Boston Bruins forward Marc Savard over four years ago, which was the beginning of the end of Savard’s career.

Cooke had an opportunity to change his ways. For a while, it looked like he had. Fans and pundits believed he reformed.  I certainly did. After the Barrie hit (and those upon McQuaid, Nichushkin and Gagner), it’s apparent he not only hasn’t changed, but has no intention of doing so.

Matt Cooke contributes nothing but unnecessary mayhem. He’s a black mark on the NHL game. A seven-game suspension for deliberately injuring Tyson Barrie was laughable. He deserves is a lifetime ban. Players like him have no business in the NHL.

Matt Cooke must go.