With teams able to bring players back from IR after three weeks, the Raiders are hoping Incognito, a four-time Pro Bowler and Pro Bowl alternate last season, can return soon.
Incognito, 37, had been dealing with an Achilles injury entering Monday night's home opener against the New Orleans Saints. He left the game after the first quarter and was replaced by rookie John Simpson.
The Raiders (2-0) had already been without the services of right tackle Trent Brown (calf) and his backup Sam Young (groin), and Denzelle Good, a guard by trade, has played the position after both went out in the season opener at Carolina.
Incognito has been one of general manager Mike Mayock's best free-agent signings since joining the Raiders after the 2018 season after retiring in 2017. Incognito, who has had his share of both on- and off-the-field issues, has not been a distraction for the Raiders since signing a one-year "prove-it" deal and then being rewarded with a two-year extension worth up to $14 million, with more than $6 million guaranteed late last season.
But with Incognito out at least through the team's bye week, Simpson, a fourth-round selection, has to step up this weekend at the New England Patriots (1-1).
"You know what, he did pretty good, it's a credit to him," Raiders coach Jon Gruden said of Simpson on Tuesday. "We put him in some tough spots...we let him fill in for Richie Incognito and he had his struggles on Wednesday [in practice] against Datone Jones. He learned some valuable lessons.
"He got thrust into a real tough situation [against the Saints]. [David] Onyemata, [Sheldon] Rankins, those are two of the best interior players in the game. He did OK in there. He handled a lot of situations very well. I give [Raiders center] Rodney Hudson and [left tackle] Kolton Miller a lot of credit for playing really good next to him. But it was a good start for John Simpson."