In excerpts posted on Twitter, Adams called Jackson a "fool" for thinking he should start over Russell Westbrook and wrote the Thunder "forgot about him pretty quickly" following his trade to the Detroit Pistons:
Jackson was Oklahoma City's first-round pick in the 2011 draft. He played with the organization for three full seasons before being traded to the Pistons midway through the 2014-15 campaign.
After the deal went down, ESPN's Royce Young reported Jackson's standing with the Thunder was "deteriorating throughout the season" in part because of his refusal to play in a November game because he was upset about not being traded.
"We have a chance of winning a championship and if Reggie is not here we still have a chance of winning a championship," Westbrook told reporters after Jackson was shipped out of Oklahoma City.
Jackson got what he wanted from the Pistons, who signed him to a five-year deal worth $80 million in July 2015. He started nearly as many games last season (45) as he did during his entire tenure with Oklahoma City (49).