Rick Carpiniello

USA TODAY Sports

NEW YORK — First period of a fairly huge Game 4 of the Eastern Conference final.

The Rangers killing what was a parade of offensive-zone penalties, most of them deserved (some not). Loose puck being chased by the Canadiens' David Desharnais, who has been fabulous in these playoffs.

With a little slide inside, Ryan McDonagh cuts off Desharnais, grabs the puck, then sidesteps Brendan Gallagher, his foil in this series. McDonagh banks a little pass off the boards to Brian Boyle, who makes a fabulous stretch pass to Carl Hagelin, speeding in behind P.K. Subban for a short-handed goal and an early 1-0 lead.

Ryan McDonagh: Seven points in the series. Subban, the All-Star, supposedly the best offensive defenseman in the series when he's not kicking people's skates out or embellishing borderline penalties, got his first point of the series in the third period.

That, by the way, is the same total as Henrik Lundqvist, who assisted on the go-ahead goal by Derick Brassard late in the second period.

But this isn't about Subban, the supposed best defenseman in the series. It is about McDonagh, the best defenseman in the series who, in case you forgot, was a wonderful gift from the Canadiens to Glen Sather and the Rangers. The best trade in franchise history.

You remember the one. June 30, 2009. Sather needed to dump Scott Gomez's contract somewhere and found a taker in Canadiens GM and legend Bob Gainey. Sather and his staff had their eye on a kid the Habs had drafted. Montreal was disappointed at his development as an offensive player, the story goes. The Rangers saw his skating ability, thought he'd be a top-four guy eventually.

But McDonagh's name was a throw-away in the story that day. Sather had dumped Gomez, and had gotten Chris Higgins and McDonagh and Pavel Valentenko for Gomez, Tom Pyatt and Michael Busto.

The gist of the trade was that Sather had cleared cap space to sign Marian Gaborik the next day. The following season, they dealt Higgins for Olli Jokinen and Brandon Prust. So the Rangers got McDonagh, two 40-goal seasons out of Gaborik, what are likely to have been the two best years of Prust's career, then dealt Gaborik for Brassard, John Moore and Derek Dorsett, who are playing in the Eastern Conference final.

Gainey is no longer around.

McDonagh is not only the Rangers' top-pair shutdown guy, he kills penalties, plays the power play, joins the offense. He played on the first pair for Team USA in the Olympics. He's going to be in the Norris Trophy conversation for a long time, and might be the next captain of the Rangers.

McDonagh's regular season came to an end April 1, when he suffered a shoulder injury on a hit by Alex Burrows in Vancouver. He came back for the playoffs, but admitted he wasn't right. After Game 4 in the Pittsburgh series, when most Rangers stunk, coach Alain Vigneault said McDonagh "hasn't played very well."

Since then, he sure has.

"He's brought his game right back to where it was before he got hurt," Vigneault said. "He was without a doubt our best defenseman, maybe to some extent our top player throughout the year."

In Game 3, twice he caught the speedy Gallagher from behind, once ramming him into the boards, once getting away with a slash. Gallagher and Daniel Briere — three times suspended for stick infractions — claimed McDonagh was a filthy slasher in a series loaded with accusations and silly suggestions.

"You can make what you want of it," Vigneault said Sunday. "Ryan McDonagh plays the game in an honorable way. He's one of the best defensemen in the league in my estimation. The Habs can have their own view."

They surely have their own view of June 30, 2008. And it isn't good.

Rick Carpiniello writes for the (Westchester County, N.Y.) Journal News