"The sides have had open and healthy discussions since the season ended," Pelissero wrote. "But with the Lions starting over again, hiring Dan Campbell as head coach and Brad Holmes as general manager, Stafford told the team he feels it's the right time to move on and team officials agreed, per sources."
Chris Burke of The Athletic reported the decision to part ways came after Stafford approached Lions management at the conclusion of the regular season, and the team made new head coach Dan Campbell and general manager Brad Holmes aware of the situation before they were hired earlier this week.
ESPN's Field Yates broke down the financial implications in Stafford's current contract:
While there's no set timetable for a trade to be completed, Pelissero's report noted one "would likely happen" before the fifth day of the new league year in March, when Stafford is owed a $10 million roster bonus.
There were rumblings last offseason that Stafford was seeking a trade, but he wound up remaining in Detroit for the 2020 campaign.
The quarterback market this offseason could be beneficial to teams looking for a new starter. Not only is Stafford reportedly on the trade block, but Jenny Vrentas and Greg Bishop of Sports Illustrated reported last week that Deshaun Watson also "wants out" due to his unhappiness with the Houston Texans.
There are also several quarterbacks in the 2021 NFL draft class with first-round potential, including presumptive No. 1 overall pick Trevor Lawrence, Zach Wilson, Justin Fields and Trey Lance.
If the Lions end up moving Stafford, they could pursue one of the top draft quarterbacks with the No. 7 overall pick.
The Lions hit the reset button in November when they fired head coach Matt Patricia and general manager Bob Quinn. They finished the regular season 5-11, their third straight losing record.
Stafford has been Detroit's starting quarterback since being selected No. 1 overall in the 2009 NFL draft. He is the franchise's all-time leader in passing yards (45,109), touchdowns (282) and completions (3,898).