There had to be a significant element of uneasiness among the Bruins brass about re-signing unrestricted free agent defenseman Tomas Kaberle to a lucrative long-term contract.

Yes, Kaberle played fairly well in the latter stages of the playoffs, but clearly his defensive-zone flaws overshadowed much of his offensive contribution. Guilty of far too many lost battles, blown coverages and costly turnovers, he often seemed sorely lacking in what's known these days as "compete level."

Now that possibility of his return is moot. Yesterday, Kaberle signed a three-year, $12.75 million deal with the Carolina Hurricanes, who then dealt veteran blueliner Joe Corvo to the Bruins for a 2012 fourth-round draft choice.

The Stanley Cup champions may well end up regarding the swap as a significant on-ice upgrade, and at a better price.

"Joe became available when we couldn't reach terms with Tomas Kaberle," said B's general manager Peter Chiarelli in a conference call. "And we felt strong about Joe as a player. Joe is a player who has a lot of experience in the league. He's a strong player, a tremendous skater. He's a very good shooter who can log a lot of minutes. He's strong on the power play. And he has extensive postseason experience.

"(He is) very quick, and good at retrieving pucks and skating up through the neutral zone and making a good seam pass. He has a terrific shot. I've seen him score often on one-timers. Stickhandling, shooting, he's very dangerous that way. With respect to the power play, I like his skating and passing. I obviously like his shot, but his skating and passing will help with the entries and be an asset on the power play."

Corvo played all 82 games for Carolina last season, and matched his second-best scoring year with 11-29-40 totals. The Illinois native twice scored as many as 14 goals in a season, and has career totals of 79-179-258 in 568 games. A right-handed shot, he has 36 power-play goals, five more than Kaberle in 334 fewer games.