Inside: Trent Brown stays in Cleveland for tests.

Medical details are scarce, but Jon Gruden was optimistic Monday about the condition of Raiders right tackle Trent Brown, who was hospitalized Sunday with an undisclosed medical issue before the Raiders’ 16- 6 win over the Cleveland Browns.

Brown, 27, couldn’t walk under his own power and was taken pregame from the locker room in front of his teammates. According to an NFL Network report, a pregame IV resulted in air entering Brown’s bloodstream requiring immediate medical attention.

The Athletic reported Brown checked out of the hospital Monday and was awaiting a flight home, and Profootballtalk.com reported the NFL Players Association would investigate the circumstances of what happened to Brown.

Gruden was not specific about the issue.

“I’m very glad to report he’s up and seems to be doing well,” Gruden said at his weekly video conference. “We’re waiting the results of some of the extensive tests they did today and yesterday. I really want to thank our medical staff. What a job they did in an emergency situation. We’re just happy he’s up and around and once we get the official word as to what’s wrong with Trent we’ll let you know.”

Gruden said there was no timetable about when Brown would be back in Las Vegas or if he’d be able to play when he did return.

“The most important thing is that we find out what went wrong,” Gruden said. “Our prayers are with Trent certainly and he’s in the best possible hands he could be right now. His availability and his status is really not up for discussion right now as far as we’re concerned.”

Brown was cleared last Friday to practice after spending nine days under quarantine after testing positive for COVID-19. Gruden said Brown had a good practice and he was scheduled to start at right tackle. But when the inactives came out 90 minutes before kickoff, Brown’s name was on the list with the Raiders saying he was ill and it was not connected to COVID-19.

Quarterback Derek Carr described a scary scene in the locker room in a post-game press conference.

“Honestly, I got a little scared for Trent, like, ‘I hope he’s OK,’” Carr said. “We had no clue what was happening. all of a sudden we come in and they’re wheeling him out and I was like ‘Bro, what’s going on?’ It was crazy.”

It was with that as a backdrop that the Raiders took the field in brutal conditions to face the Browns.

“I think the big thing is we were all shaken up pretty good,” Gruden said. “You get shook up when you see one of your own go down and you don’t know what’s wrong with him. We were able to assure our players he was in good hands, his signs were vital, he was doing good. We said a prayer for Trent before the game and we tried to win the game for him. It’s something that’s on our mind. It’s weighing heavily on us right now. We hope he’s OK.”

PARKER TO THE RESCUE >> There were some raised eyebrows when the Raiders traded David Sharpe to Washington at the close of training camp and kept Brandon Parker. Parker has more than validated the Raiders’ faith in him, and earned a game ball after playing 42 snaps against Cleveland. Parker replaced Sam Young, who made it 23 snaps before being removed with a knee injury that has bothered him all season.

“Brandon did a good job, not only filling in for Trent, but for filling in for Sam Young,” Gruden said. “He allowed us to do some things offensively, which was really important.”

Parker was originally going to be inactive until Brown had to be hospitalized because of a pregame medical issue. Parker also finished up for Young against Tampa Bay the previous week, playing 48 snaps. He was a third-round draft pick out of North Carolina A&T in 2018.

ABRAM AS A BLITZER >> Gruden, who compared Josh Jacobs to Walter Payton after Week 1, thought safety Johnathan Abram reminded him of another respected opponent when asked about the safety’s ability as a blitzer.

“I compared him to the exCharger, Patriot great Rodney Harrison,” Gruden said. “He just has that physical gameday presence that we feel like we need back in this organization. He still has a long way to go to become a great safety, but I think you see the splash plays that he’s capable of making. He brings us some leadership and some energy that we really need in the backend.”

MEDICAL UPDATES >> Cornerback Damon Arnette (thumb surgery) will go to Houston this week to have his broken hand evaluated. Gruden said he could come off injured reserve and be available to face the Los Angeles Chargers on Sunday.

• Defensive tackle Maurice Hurst left Sunday’s game against the Browns after just six snaps with an ankle injury and may not face the Chargers.

“His availability is up in the air. Fortunately, we don’t think it’s serious,” Gruden said.