In nine days, the National Hockey League will close its trading season for the remainder of the 2017-18 campaign. By 3 p.m. — or soon after when all the trades are officially announced — the buyers hope to add a key cog or two to increase their Stanley Cup aspirations, while the sellers try to stockpile prospects and draft picks to build for the future.

One of those teams expected to sell high is the New York Rangers. The likes of Rick Nash, Michael Grabner and Ryan McDonagh are just a few of the marquee names in the rumor mill. All three would fit the Bruins’ needs in the stretch run, but the trade talk around McDonagh, in particular, is getting quite the traction.

As with any trade, GM’s will have to part ways with certain assets to acquire their desired player. McDonagh is no exception.

The Rangers captain has a $4.7 million cap hit through the 2019-20 season. Though the Bruins would have to shed cap space, McDonagh’s contract is quite friendly for a player of his caliber, and he fills a need as a top-four left-shot defenseman.

Acquiring McDonagh will likely cost the Bruins a first-round pick, a top-tier prospect (like Trent Frederic or Jack Studnicka) and one of Danton Heinen or Jake DeBrusk. The latter found himself the subject of the rumor mill on Friday in a tweet by Jim Matheson.

I'm hearing NYR would want Bruins' rookie Jake DeBrusk included in any deal for Ryan McDonagh. Ironic, since former Oiler GM Sather traded for Jake's dad Louie when he sent Mark Messier to NYR in 1991.

— Jim Matheson (@NHLbyMatty) February 16, 2018

Including DeBrusk or Heinen plus a prospect and a first round seems like a stretch on the surface. But there’s a reason why this could work if Don Sweeney wants to part with one of his rookies to acquire McDonagh.

For one, McDonagh’s arrival would immediately give the Bruins D a shot in the arm assuming they don’t part ways with Brandon Carlo. A top four of Zdeno Chara, Charlie McAvoy, McDonagh and Carlo on the back end would give the Bruins two reliable shutdown pairs come playoff time.

As for anyone who would fill DeBrusk’s role, look no further than Ryan Donato, who is poised to jump to the NHL following his Olympic duties with Team USA — or after Harvard’s season comes to an end. Either way, the Crimson standout will be joining the Black and Gold sooner rather than later.

But there are also some concerns about this rumored package for McDonagh.

First, the Bruins would have eight reliable defensemen on the back end by adding McDonagh. Kevan Miller or Adam McQuaid would likely be moved elsewhere, but that would also leave the Bruins with four good left shot blue-liners in Chara, McDonagh, Torey Krug and Matt Grzelcyk. The ex-Boston University standout is a candidate to go back to Providence, but Grzelcyk has shown he can play at the NHL level and a return down I-95 south isn’t necessary.

Second, there’s the hole that it would leave up front if DeBrusk or Heinen were to move. Sure, Donato could be a ‘de facto’ upgrade in a top-six or top-nine role, but there’s always a risk involved putting a young player into the fire. It worked for McAvoy last year — albeit under different circumstances — but it’s still a crapshoot.

And then there’s the whole future contract situation. McDonagh’s UFA status comes at the same time when McAvoy and Carlo will be given bigger paydays after their entry-level contracts expire in 2018-19; not to forget, Chara’s potential short-term deal — between one and three years — come the off-season.

McDonagh, Erik Karlsson, Oliver Ekman-Larsson and Drew Doughty are all scheduled to hit the open market in the summer of 2019. The blue-line quartet will command big money so it’s far from a guarantee that the Bruins would keep McDonagh even after next season.

The Bruins sit three points behind the league-leading Tampa Bay Lightning entering Saturday’s tilt with the Vancouver Canucks. They are the league’s hottest team since mid-November thanks to a healthy blend of youth and veterans. Adding McDonagh wouldn’t be a bad thing but there’s also a thought that leaving the locker room chemistry alone is pretty enticing.

Of course, injuries can change Sweeney’s course of attack, but the Bruins GM is in a good spot. Adding McDonagh or any other hot commodity — at the right price — would be a luxury. But staying pat, and potentially adding another key cog in the off-season through trade or free agency, wouldn’t be a bad thing either.