Raiders’ Gabe Jackson carted off practice field with leg injury

NAPA — The Raiders are awaiting word on the status of right guard Gabe Jackson, who was carted off the field with a leg injury during Thursday’s joint practice with the Los Angeles Rams.

Jackson is one of the Raiders most consistent lineman, and the hope was teaming him with Trent Brown would be create of the NFL’s most effective tandems on the right side of the line.

“We’re concerned, obviously, really concerned about him,” Raiders coach Jon Gruden said. “We’ll get more information here when we can be specific for you. I don’t want to speculate.”

According to one source with knowledge of the situation, “It doesn’t look good.”

Jackson’s mishap was the first potentially major injury of camp. Wide receiver Antonio Brown missed practice again with what is believed to be a condition similar to frostbite on both feet as a the result of a reported cryotherapy session.

Gruden continued to decline comment on anything to do with Brown.

“He’s still gathering (information),” Gruden said. “I don’t have any information other than that.”

Asked if the reports of frostbite were correct, Gruden said, “I’m not going to get into the exact nature of the feet. I’m just not.”

The Raiders believe Brown will be back soon, even if they don’t know have a timetable. As for Jackson, they’ll have to keep their fingers crossed.

Gruden said Jackson got “rolled up a little bit” during a team period. Moments earlier, Jackson had been involved in a minor skirmish with Rams defensive tackle Aaron Donald.

Jackson struggled to stand before he was placed on a cart and driven toward the field house and weight area where he was checked out by trainers. Owner Mark Davis made his way to the restricted area and spent between 10 and 15 minutes there before reemerging to watch practice.

With Jackson out, Denver Kirkland took reps with the first team at right guard as did Jordan Devey, who is also the Raiders’ backup center to Rodney Hudson.

The Raiders are already thin at guard and won’t left side starter Richie Incognito on the left side for the first two games of the season as he serves a suspension for violating the NFL’s personal conduct policy. Jonathan Cooper was signed as a free agent before camp opened and the plan is to work him in at left guard as the season approaches.