Impending unrestricted free agent Joe Thornton agreed to a 3-year, $21M extension with the San Jose Sharks on Saturday. For San Jose, this marks the third time in the last four months that they locked up a key member of their core before that player reached free agency. In late June, right before the July 1st free agency period, San Jose signed forwards Patrick Marleau (who would have been a UFA) and Joe Pavelski (a pending restricted free agent), both for less than what they could have received on the open market, and both to 4-year deals. The key for San Jose is that Thornton?s 3-year extension will expire in 2013-14, the same season that the big contracts of Marleau, Pavelski, Dany Heatley and Dan Boyle all come off the books; in fact, the Sharks do not have a single player signed beyond the 2013-14 season. So while it seems like signing core players to ?lifetime? contracts is the modus operandi for many GMs in the salary cap era, San Jose?s Doug Wilson has done a remarkable job locking up his core members without handcuffing himself. Three and four-year deals are traditionally easy to move, and much more so than the ?lifetime? contracts. A ?lifetime? contract is typically for eight or more years, depending on age, and essentially locks a player up until his retirement. Think Marion Hossa, Zdeno Chara, Duncan Keith, Ilya Kovalchuk, Alexander Ovechkin, Nicklas Backstrom and Rick DiPietro. Additionally, the $21M total of Thornton?s extension is far below market value. It will come with a $7M cap hit, which is below his current $7.2M deal. On the open market, Thornton probably could have received in excess of $8M annually, and likely would have received at least one ?lifetime? offer (essentially, an 8-year deal, as he will turn 32-years-old next summer). But instead of catering to the new team captain, Wilson stuck with the team?s established contract structure and did not sway from his plan. Thornton?s accolades are almost endless: 6-time All-Star, 2-time Olympian, gold medalist, 2006 Art Ross winner, 2006 Hart Trophy winner as MVP, five straight years of 60+ assists, six straight years averaging more than a point-per-game. And by all accounts he is a quality leader and teammate after succeeding the retired Rob Blake as team captain. And after breaking through with a career-high 12 points in the playoffs last year, there looks to be no downside for the Sharks on this deal. Grade for San Jose: A+ Obviously, after the endless praise bestowed upon GM Doug Wilson and the Sharks for their end of this deal, Thornton?s grade won?t be as stellar. As indicated above, he is turning down the possibility of receiving a ?lifetime? deal, in the range of 8-years, $60-$70M. Now he potentially puts himself into a position where he may have to test the free agent market at age 35, and depending on the next CBA, could struggle to receive more than a two or three year offer; he could also receive less money depending on the salary cap figure at that time. The other argument is that Thornton took a pay cut to stay with a team and franchise that he loves and is comfortable with. He is now the team captain, genuinely enjoys playing in San Jose, and word is that he and his wife are building a home in the area. The pay cut allows the team to keep building a winning hockey club in the salary cap era. Players should be commending for taking pay cuts for the good of the team, because the reality is all athletes are paid far more than they deserve. Team-first attitudes when it comes to contract negotiations are few and far between, and it?s nice to see a premier player with that attitude, however unbeneficial it may seem. Grade for Thornton: B+ Nick can be reached via email nickobergan@hotmail.com or on twitter @NickObergan