Per ESPN's Adam Schefter, Mack will hold out as he seeks a long-term contract extension.
Mack's contract has been a hot topic of discussion for the Raiders this offseason. The two-time All-Pro will make $13.8 million this year in the final season of his rookie contract.
Raiders head coach Jon Gruden told reporters last week Mack's deal is one issue the team needs to resolve.
"That might be the toughest decision I have to figure out right now," Gruden said. "We're not the only team that's faced with that. It's tough. It's part of this business, and we'll just keep our fingers crossed."
Per The Athletic's John Middlekauff, Mack and the Raiders are "not close at all" in their negotiations. He also said to "get ready for an ugly situation."
Mack has played outside linebacker and defensive end in his NFL career. Denver Broncos star Von Miller is the highest-paid outside linebacker with a deal that includes $42 million in guarantees and $114.5 million total.
New York Giants defensive end Olivier Vernon has the highest guarantee ($40.5 million) among players at his position. Houston Texans star J.J. Watt has the highest total value at $100 million for a deal he signed in 2014.