Chiarelli has confidence in Lucic & others/By S. Bradley

The Bruins’ two trades today tell us as much about what Peter Chiarelli thought he needed to upgrade as they do about what he loves about his squad.

We always knew he wanted to add some offensive flair to his back end, and now we know that he also was looking for some more experience in his bottom six. But just as interesting is the apparent 100 percent vote of confidence he silently gave to his cornerstone forwards, baking on them to get the Bruins where he wants them to be come spring.

For those out of the loop and actually working a real job today, as first reported accurately by Fluto Shinzawa of the Boston Globe, the Bruins shipped former first-round pick Joe Colborne, their own first-round pick in 2011 and a second-round conditional pick in 2012 (it goes to Toronto if the Bruins go to the finals or re-sign Kaberle) to the Maple Leafs for Tomas Kaberle.

As a second move to create cap space, Chiarelli shipped Blake Wheeler and Mark Stuart, his last two Minnesota natives, to Atlanta, where there’ll be reunited with former Bruins assistant coach Craig Ramsay. In exchange, the Thrashers sent the Bruins center Rich Peverley and defenseman Boris Valabik, who’s ticketed for the Providence (AHL) farm club.

In Kaberle, the Bruins finally end their “puck-moving defenseman” search, which seemed like it lasted longer than the expedition to find Noah’s Ark. Is he enough to make their back end an elite group? No. What Kaberle does is give the Bruins a chance to have two balanced, effective power-play units without Mark Recchi wearing himself out at one point. Kaberle should also strengthen the transition game, without weakening the club’s defensive-zone coverage, although he has been known to lose his share of 1-on-1 battles and isn’t going to scare anyone with his physicality.

With Peverley, added to a group that includes Shawn Thornton, Gregory Campbell, Chris Kelly and Daniel Paille, the Bruins now have a solid, veteran bottom six that can grind out offensive opportunities, win big faceoffs and not make head coach Claude Julien worry too much when an opposing top line gets on the ice and he can’t get a line change. With Wheeler gone, Kelly and Peverley will be more-than-adequate replacements 5-on-5 and on the penalty kill.

There’s no doubt the Bruins are better on their back end. From the start of the season until now, they’ve gone from having Matt Hunwick and Stuart in the lineup to Kaberle and Steven Kampfer. Even if Kampfer finds himself on the sidelines, Adam “Lone Wolf” McQuaid’s improvement still makes the Bruins’ sextet on D better than it was Oct. 9 in Prague.

Up front, Boston is also better today than yesterday as far as this season. Wheeler might someday soon find his niche as a defensive forward, or might discover the will to use his size to be a power forward, but that wasn’t going to happen between now and the end of this season in black and gold.

What this trade tells me more than anything, however, is that Chiarelli is content with his prime handful of forwards – Patrice Bergeron, David Krejci, Nathan Horton, Michael Ryder and Milan Lucic – and their ability to form a championship-caliber offense. There’s not a legitimate, consistent sniper in the bunch. But that seems like the gamble Chiarelli is willing to take. Or he just knows that there aren’t going to be any 30-goal scorers available, or the price to get one will be too steep.

This season we have seen the Bruins improve into a team that’s fifth in the league in scoring despite an abysmal power play. They’ve done it with balance and with the emergence of Brad Marchand, Campbell and Thornton as unlikely sources of offense that have offset the struggles of Horton and Krejci. Michael Ryder has at least regained his form of two years ago. Mark Recchi and Tyler Seguin, Boston’s two extremes on the age chart, have chipped in. And, of course, Bergeron has been fulfilling his potential after a couple years as strictly a shutdown center.

That playoff defenses might be able to solve Marchand, and Campbell and Thornton might not see as much ice time in the postseason doesn’t seem to bother Chiarelli. He’s also obviously not overly concerned with the hot-and-cold nature of Krejci’s and Ryder’s play, or that Horton has become Mr. Cold instead of the streaky player the Bruins could use to get hot at times when others aren’t.

Obviously, the Bruins are hoping Kaberle’s panache will create more room and chances for the forwards at even strength and on the power play. It should also make Zdeno Chara more of a factor with Kaberle either next to him or leading an excellent second pair. That could well happen. I’m just not sure you win three or four rounds of playoffs with a bunch of streaky forwards that need so much assistance. You’d like to see at least one forward with the type of speed and/or stickhandling ability to create his own offense and bury more pucks than he fires onto the glass.

Chiarelli took a gamble today in dealing Colborne and a future prospect or two for a veteran defenseman that could turn out to just be a two- or three-month rental. But to me, his real roll of the dice – if he doesn’t do anything major over the next 10 days – is putting all his chips in with the five or six-man forward core he has been relying on since Day One in the 2010-11 season.

He has 10 more days to make a big move to solidify that group, or those players have two to four more months to prove me wrong and Chiarelli right.