If an NHL general manager is looking to transform his team with a trade, his best bet would be to dismiss Wednesday’s trade deadline possibilities and look farther ahead. Most of the big team-shifting trades occur when the league convenes in late June for the entry draft.

But in-season trade deadline acquisitions still matter.

In the past few years, we’ve seen it all – the typical rental deals, futures deals and, yes, even the odd blockbuster. All you have to do is look back at the last half-dozen Stanley Cup winners to see how significant deadline pickups can be.

Now, for Bruins GM Don Sweeney, it is highly doubtful that by Wednesday he’ll find a deal that will make his team a Cup contender. But if he plays his cards right, he just might find a building block or two.

Here’s a look at the in-season deals the last six champions have made and how it helped them hoist the Stanley Cup:

 2015-16 Pittsburgh Penguins: The team went through as much overhaul as any champion in recent memory, both from within and outside the organization. The big change came when Mike Sullivan took over for Mike Johnston behind the bench after 28 games. Sullivan began integrating some of his AHL charges – Conor Sheary, Bryan Rust, Tom Kuhnhackl and, most importantly, goalie Matt Murray. But GM Jim Rutherford also obtained players who fit Sullivan’s speed game, acquiring defenseman Trevor Daley from Chicago for fellow blueliner Rob Scuderi. About a month later, Rutherford pulled off the move that put the Pens over the top, getting speedy Carl Hagelin from Anaheim for forward David Perron and defenseman Adam Clendening. Hagelin would form the HBK line with Nick Bonino and Phil Kessel that was so effective in the playoffs.

By the time deadline approached, the heavy lifting was done but there was still work to do. Rutherford acquired defenseman Justin Schultz from Edmonton for a third-round pick. He played the final 18 games of the regular season, logging a plus-7, and then all 15 playoff games, contributing four points.

 2014-15 Chicago Blackhawks: The Blackhawks were active around the trade deadline and landed an impact player. GM Stan Bowman acquired center Antoine Vermette for a first-round pick and middling defense prospect Klas Dahlbeck. Vermette was the kind of straight rental most often associated with deadline deals. After initial trouble fitting in, Vermette was a key contributor to the playoff run. In the Western Conference finals against the Ducks, Vermette scored the double-overtime winner in Game 4. Bowman also swapped bottom forwards with San Jose, obtaining Andrew Desjardins for Ben Smith and Desjardins has been a serviceable role player. The Hawks also picked up Kimmo Timonen from Philadelphia for a second-round pick. The veteran Timonen had not played to that point because of blood clots. He played in 16 regular-season games and 18 playoff games but did not have a point.

 2013-14 Los Angeles Kings: The Kings pulled off a whopper when they obtained Marian Gaborik, who was not playing well in Columbus, for Matt Frattin and second- and third-round picks. Gaborik netted 14 goals in the playoff run that produced the Kings’ second Cup in three years. LA also picked up defense prospect Brayden McNabb along with forward Jonathan Parker and two second-rounds picks for forwards Nicolas Deslauriers and Hudson Fasching. McNabb became a regular for the Kings while Deslauriers is a regular brawler for Buffalo.

 2012-13 Chicago Blackhawks: In the lockout-shortened 48-game season, the Blackhawks made one move at the deadline, acquiring two-way centerman Michal Handzus from San Jose for a fourth-round pick. Handzus was near the end of a fine NHL career, but contributed to the Cup run, posting 3-8-11 totals in 23 playoff games, including a short-handed goal against the Bruins in Game 4 of the Stanley Cup finals, a Hawks win.

• 2011-12 Los Angeles Kings: The Columbus Blue Jackets contributed greatly to this Kings’ championship as well. A few days before the deadline, the Jackets traded Jeff Carter – who had cost Columbus the services of Jake Voracek less than a year before – to LA for defenseman Jack Johnson. Carter not only had a strong playoff campaign (8-5-13 totals in 20 games), but he helped cement the Kings’ heavy, hard-to-play-against identity that would earn them a second Cup in 2014.

• 2010-11 Bruins: Former GM Peter Chiarelli performed a fairly extensive facelift around deadline day. First, he acquired Chris Kelly for a second-round pick from Ottawa. Then a few days later, he obtained defenseman Tomas Kaberle from Toronto for Joe Colbourne, a first- and a second-round pick. Finally on deadline day, he shipped Blake Wheeler and Mark Stuart to the Atlanta Thrashers for Rich Peverley and Boris Valabik (the latter a prospect who never panned out.) Kaberle seemed to be the big get at the time, but he didn’t have the impact most expected. But Kelly and Peverley joined Michael Ryder to form a third line that proved pivotal in the B’s getting past the Canadiens. Peverley then stepped in for the injured Nathan Horton on the first line in the finals against the Canucks.

Bottom line? If Sweeney wants to be a player in the market, it doesn’t mean he’s deluded into thinking this is the year for his team.