"We're going to be second-guessed until the cows come home on this. I understand that," Gruden said, per Tom Pelissero of NFL Network.
"It wasn't my goal to trade Khalil when we got here," he added. "One of the reasons I'm here is because of him."
The coach noted the deal was forced after the contract standoff where Mack held out through training camp. The defensive end agreed to a six-year, $141 million extension with the Chicago Bears shortly after Sunday's trade, per ESPN's Adam Schefter.
Oakland acquired four draft picks in the deal, including first-round picks in 2019 and 2020, while Chicago also received a second-rounder and a conditional fifth-round pick. Interestingly, Gruden said he didn't have a hand in sending the second-round pick along with Mack, per Schefter.
This seemed to indicate general manager Reggie McKenzie was involved in the actual negotiations, although Bleacher Report's Mike Freeman reported he didn't want to trade Mack.
Marcus Thompson of The Athletic also indicated the coach was trying to deflect the blame:
McKenzie did at least agree with Gruden that this wasn't a long-term plan.
"It was in the final hour that it kind of just hit and it hit hard and heavy," the GM explained, per Josh Dubow of the Associated Press. "It was not the plan to trade him at all."
Meanwhile, Gruden noted the team's approach in both the short and long term following the trade.
"We're going to do everything we can to win," he said. "We also have to build this football team. We've had one winning season in 14 years."