Source: Koppen returning to Patriots

Center Dan Koppen will re-sign with the Patriots after spending a month on the free-agent market, a league source told ESPNBoston.com. The deal is a two-year pact with a maximum value just shy of $6 million.

Koppen, 32, has spent his entire career in New England, starting 120 of 121 regular season games.

After suffering a broken left fibula in the Patriots' opening game last season, there was hope that Koppen would be able to make a late-season return, but he was placed on injured reserve on Sept. 21, ending his season.

The move to re-sign Koppen comes weeks after the Patriots re-signed Dan Connolly, who was Koppen's replacement at center last season. Connolly received a three-year, $9.7 million deal, suggesting that Koppen, who visited the Tennessee Titans earlier this month, would no longer have a role in New England.

Instead, Koppen re-joins a crowded interior offensive line for the Patriots that includes guards Logan Mankins and Brian Waters, who were each named to the Pro Bowl last season, although Waters said after the team's loss in Super Bowl XLVI that he would consider retirement.

The Patriots also signed former second-overall pick Robert Gallery last month, who can play both guard and offensive tackle, while they return offensive linemen Connolly (11 starts in 2011), Ryan Wendell (three starts), and Nick McDonald (two starts).