The Washington Redskins will sign free agent defensive lineman Terrell McClain to a four-year deal when the free agency begins at 4 p.m. ET, a source confirmed to ESPN's John Keim.
The Redskins also have signed safety D.J. Swearinger, a source told Keim.
The news of McClain's agreement was first reported by the Dallas Morning News.
The Redskins lost defensive tackle Chris Baker in free agency to the Tampa Bay Buccaneers. McClain can play multiple spots along the front, having done so in Dallas.
McClain would become the third Cowboys player to leave the team in free agency, joining safety Barry Church (expected to sign with the Jaguars) and guard Ronald Leary (likely to sign with Broncos).
After injuries limited his effectiveness during his first two seasons with the Cowboys, McClain, 28, won the starting nose tackle job in training camp over free-agent signee Cedric Thornton and started 15 games last season.
He led the Cowboys' defensive linemen with 40 tackles and had a career-high 2.5 sacks. In addition, McClain had three tackles for loss, eight quarterback pressures and two forced fumbles. He has the ability to play both tackle spots, and Cowboys defensive coordinator Rod Marinelli was a fan of his ability to penetrate gaps and make plays behind the line of scrimmage.
McClain, who missed 14 games in 2015 because of a toe injury, joined the Cowboys as a free agent in 2014 after the Texans opted not to tender him a contract as a restricted free agent. Picked by the Panthers in the third round of the 2011 draft, McClain has 90 career tackles with three forced fumbles and 4.5 sacks.
Swearinger, 25, had a solid season during his contract year with the Cardinals, as he finished 2016 with career highs in interceptions (three) and sacks (two). His 64 tackles also were the second most of his career.
Most importantly, Swearinger showed his versatility by playing both free safety and strong safety, starting 12 games for an injury-depleted Cardinals secondary.
ESPN's Todd Archer and Josh Weinfuss contributed to this report.