ALAMEDA, Calif. -- While Jon Gruden has bemoaned the lack of a pass rush through two winless games in his return to the NFL, the Oakland Raiders coach said he has no second thoughts on trading Khalil Mack to the Chicago Bears on Sept. 1.

"No, it doesn't make me regret the trade," Gruden said Monday in his weekly media conference. "We made the trade. We made the trade, you know there's going to be hindsight, 50-50, all that stuff, but we would have loved to have had him here. I'm not going to keep rehashing this."

Mack, a two-time All-Pro on a Pro Football Hall of Fame trajectory, held out from the Raiders all offseason in hopes of a contract extension as he was under contract to make $13.8 million on the fifth-year option of his rookie contract in Oakland. When it became apparent to Gruden and the Raiders that Mack would not be reporting to the team before the start of the season, Oakland dealt him to Chicago.

The Bears got Mack along with the Raiders' second-round draft pick in 2020 and a conditional fifth-rounder in 2020 while Oakland received the Bears' first-round picks in 2019 and 2020, a sixth-rounder in 2019 and a third-rounder in 2020.

Raiders coach Jon Gruden is still looking for his first win in his return to the NFL. Dustin Bradford/Getty Images

Mack, who had 40.5 sacks in four seasons with the Raiders, then signed a six-year, $141 million extension with $90 million guaranteed, a record deal for a defensive player.

He had a strip-sack fumble recovery and a 27-yard pick-six in the first half of his Bears' debut against the Green Bay Packers. However, he was mostly quiet in the second half of the Packers' comeback win.

Oakland, meanwhile, has just two sacks in two games -- defensive end Bruce Irvin got the Los Angeles Rams' Jared Goff in the opener and rookie defensive tackle Maurice Hurst took down the Denver Broncos' Case Keenum on Sunday -- and lack of pressure in the closing minutes of Sunday's 20-19 loss at Denver allowed Keenum to pick Oakland apart for the game-winning drive.

"I would have loved to have coached him, loved to have had him here," Gruden said of Mack. "But he's not here and, you know, somebody's got to step up. We've got to keep building our football team; that's what we're going to do and hopefully we see more from Arden Key. Hopefully we see more from P.J. Hall, when he gets healthy, and hopefully we prove that, in the long term, we did the right thing."