The Capitals re-signed Karl Alzner to a contract that counts almost $400,000 less against the salary cap than what his original deal did. (Toni L. Sandys/THE WASHINGTON POST)

The Washington Capitals have garnered plenty of attention this offseason for the addition of five veteran free-agents to the dressing room, but on Friday the team ensured that one of its young home-grown defensemen will remain in the fold for two more years.

Washington signed Karl Alzner to a two-year contract worth $2.57 million, which is widely considered a bargain price for the 22-year-old who established himself as half of the Capitals’ shut-down pairing in his first full NHL season.

Alzner, 22, will earn $1.3 million in 2011-12 and $1.27 million the following year, while the contract translates to an annual salary cap hit of $1.285 million — $390,000 less than what the final year of his entry-level deal counted against the cap.

In a conference call with reporters, Alzner admitted that some salary was left on the negotiating table. But as a restricted free agent without arbitration rights or any offer sheets from other NHL teams, his leverage was limited.

“There was no other offer out there, so that was all I had. So it was either take it or leave it,” Alzner said. “We definitely had to come down a bit and Washington had to go up a bit so we’re happy that we got something done. “

Barring a major trade, Alzner’s new contract may be the last significant splash of the offseason for the Capitals, who have already signed free-agents Jeff Halpern, Joel Ward, Troy Brouwer, Roman Hamrlik and Tomas Vokoun.

The Capitals sit roughly $890,000 over the NHL’s 2011-12 salary cap of $64.3 million after the moves, including the trades of Semyon Varlamov to Colorado and Eric Fehr to Winnipeg. Teams are allowed to exceed the maximum by up to 10 percent during the summer and only must comply with the salary cap by the start of the regular season.

Fitting the roster under the cap ceiling likely won’t be a problem for Washington, though. General Manager George McPhee has said repeatedly that defenseman Tom Poti (groin) is fighting for his career and could be placed on the long-term injury list at the start of the season to free $2.875 million in cap space. McPhee has also alluded to other, unspecified players possibly being unable to start the season on time because of injury.

Capitals notes: Washington’s week-long development camp concludes Saturday with a scrimmage at 10 a.m. at Kettler Capitals Iceplex. . . . The Capitals signed restricted-free agent Francois Bouchard to a one-year contract. Bouchard recorded 24 points in 74 games with Hershey last season.