Mack has been at the center of a major contract dispute with the team and has yet to report to the team.
Mack, the No. 5 overall pick of the 2014 draft, had stayed away from the Raiders' voluntary offseason training program and held out of the team's mandatory three-day minicamp in June.
NFL Network's Ian Rapoport reported Saturday morning that the Oakland Raiders traded their star defensive end to the Chicago Bears for two first-round draft picks and possibly more.
The Raiders exercised their fifth-year option, worth almost $14 million, on Mack.
The move is a true blockbuster, as well as one that new Raiders head coach Jon Gruden apparently was eager to make.
It is bad enough for the Raiders that they just lost their best player and if they truly are in cash flow issues, it could be getting better no time soon. (He's) really a great guy.
Raiders players, including Mack's best friend, Derek Carr, have thoughts on this.
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