A day after the Raiders sent the two-time first-team All-Pro and 2016 NFL Defensive Player of the Year to the Bears, along with a second-round draft pick in 2020 and a 2020 conditional fifth-rounder, for the Bears' first-round picks in 2019 and 2020, a sixth-rounder in 2019 and a third-rounder in 2020, Gruden also took issue with the notion that he wanted to trade Mack, while Raiders general manager Reggie McKenzie wanted to re-sign him.
"They're trying to divide us," Gruden said. "People are trying to divide us: 'I wanted him gone, he wanted him here.' We made a decision as an organization. [Owner] Mark Davis, [executive] Tom Delaney, we all got the information and we made a decision, together. And I'll just say what [Reggie] said -- I read what he said yesterday -- it's a decision that we all came to.
"I know there's maybe some feeling that maybe I was involved in a day-to-day negotiation. I had nothing to do with it. We were at a standoff and something had to happen, and here we are."
Mack, who held out and had not been at the Raiders' practice facility since the end of last season, was under contract and due to make $13.8 million this season on the fifth-year option of his rookie deal. The Raiders could have used the franchise tag on him next season.
Instead, the Raiders fielded offers and Chicago's won out. The Bears signed Mack to a six-year, $141 million extension with $90 million guaranteed, a record for a defensive player, a source told ESPN's Adam Schefter.
McKenzie said the Raiders made an offer to Mack at the start of the league year in March.
"I don't believe we were anywhere close to where the Bears were," Gruden said. "The Bears made us an offer that we thought was really unique and very, very tough to say goodbye to a great player, but here we are today."
On Sunday night, Mack tweeted his gratitude to the Raiders fan base.
A day before the Mack trade, the Los Angeles Rams signed defensive tackle Aaron Donald to a six-year, $135 million deal with $87 million guaranteed.
"That pretty much set the stage of what it was going to be," Gruden said. "And $90 million guaranteed is an astronomical number. It's phenomenal, I think, for the players. Great for him, obviously. But that was something we could not do."
Especially not with quarterback Derek Carr already entering Year 2 of a five-year, $125 million extension and sitting on a $25 million salary cap number.
"I don't know how many teams have done that," Gruden said. "Aaron Donald got signed, they don't have a quarterback that has been re-done yet. I think the Bears made this trade, [Mitch] Trubisky is still on his rookie deal. It's tough when you have two players that are the highest paid at their positions, so the economic part of it certainly weighs in."
Gruden's brother, Jay, oversaw a similar scenario in Washington last season with quarterback Kirk Cousins and cornerback Josh Norman boasting cap numbers of $24 million and $20 million, respectively. Washington went 7-9.
"We've got free agents on our team that are going to be [up] next year. We've got to find a way to bring them back," Gruden added, and receiver Amari Cooper's fifth-year option for 2019 has already been exercised. "So you've got to field a 53-man roster and there are some implications of having two players making that much money. That's no mystery to anybody."
Gruden was also asked why the Raiders did not simply wait Mack out to see if he would report under his current contract.
"We have waited," Gruden said. "We waited and waited, and the Rams game was looming. Our feeling was he was not going to report anytime soon. Like I said, I saw the Redskins go through it with Kirk Cousins. It was a long process. You can wait it out, you can franchise him, you can force him to play, but we made a decision and we're going to stand by it.
"We're going to do everything we can to win and put together the best team possible. We have a lot of holes, and we have to do what we can to fill them."
Gruden: We'll be 'second guessed until the cows come home'
Raiders coach Jon Gruden says the team was at a "standoff" with Khalil Mack and describes how the organization decided to trade him.