FOXBOROUGH, Mass. -- The New England Patriots have agreed to trade longtime right tackle Marcus Cannon to the Houston Texans in a deal that involves a swap of mid-to-late-round draft picks, sources told ESPN.

Cannon had opted out of the 2020 season, and sources said a catalyst for the trade was that he had not reported to the Patriots for a physical and workout -- because of COVID-19 considerations -- with the team's other players who opted out.

The 6-foot-6, 335-pound Cannon, a non-Hodgkins lymphoma survivor, is from Texas. He also played in college at Texas Christian.

The trade cannot be made official until the start of the league year, which begins Wednesday at 4 p.m. ET.

Houston currently has two starters at offensive tackle under contract: left tackle Laremy Tunsil and 2019 first-round pick Tytus Howard. If both remain on the roster before the start of the 2021 season, Howard could move back inside. During his rookie season, Howard played left guard and left tackle before being moved to right tackle.

Cannon has appeared in 115 career NFL regular-season games (69 starts) and also 19 playoff games (11 starts). He was part of three Super Bowl championship teams in New England, which had selected him in the fifth round of the 2011 draft.

The Patriots, who previously agreed to a trade for Las Vegas Raiders offensive tackle Trent Brown, will save about $6.3 million on the salary cap by trading Cannon.

The deal would be the first swap between Patriots coach Bill Belichick and his longtime director of player personnel Nick Caserio, who is in his first season as Houston's general manager.

The Boston Globe first reported the trade.

ESPN's Sarah Barshop contributed to this report.