While the stalemate with Pro Bowl wide receiver Vincent Jackson continues, the San Diego Chargers reached an agreement on a five-year contract extension with Pro Bowl offensive tackle Marcus McNeill on Monday, according to a source familiar with the situation.

The five-year extension will be tacked on to the one-year, $630,000 tender McNeill accepted last month. The new deal will be signed by Tuesday.

The contract ties McNeill to the Chargers franchise through 2015 and gives him the financial security he sought when he decided to hold out until Sept. 25, the day he reported to San Diego and signed his tender.

After missing the first five games of the season, McNeill will be eligible to play Sunday against St. Louis, as San Diego tries to improve upon its 2-3 record. The Chargers officially activated McNeill on Monday.

With McNeill out of the lineup, Brandyn Dombrowski -- a former practice squad player who played both right guard and right tackle last season -- stepped in. But Chargers quarterback Philip Rivers should have more time to throw with McNeill watching his blindside.

Meanwhile, Jackson continues to sit out and many people around the league think his absence could last the entire 2010 season.

Adam Schefter is an NFL reporter for ESPN Insider.