INDIANAPOLIS — Raiders middle linebacker Nick Roach, who missed the entire 2014 season after suffering a concussion in a preseason game, is still having headaches and is not expected to return next season, team sources said.

General manager Reggie McKenzie was asked Wednesday at the NFL combine if he expected Roach to play in 2015.

McKenzie said, “That decision is up to Nick and the medical staff. I am not going to rush him to play when mentally he’s not ready.”

Roach continues to work out at the Raiders’ facility but has declined to talk about his status.

After playing every defensive snap for Oakland in 2013, Roach suffered the concussion in a preseason game against Green Bay on Aug. 22 and briefly returned to practice in September. But Roach was limited to individual drills in the background before being shut down for the year after the Raiders fell to 0-4.

Roach said in September that he had “two or three” other concussions in the past.

“You’ve got to start looking out for the player,” McKenzie said. “We’ll continue to communicate with the medical staff and I’ll talk to Nick … As much as we’d love him to be our signal caller on defense, I don’t want to risk lifelong injury if he goes out there.

“Especially if he has any, not discomfort, but any type of feeling within him that something’s not right. And for it to last this long is not a good thing.”

The middle linebacker position moves to the top of the Raiders’ need list — along with a No. 1 receiver, an interior offensive lineman and a couple of defensive linemen. Third-year player Miles Burris made the move from outside linebacker to the inside to replace Roach last season, but struggled at times shedding blocks and making tackles.

Some other tidbits from McKenzie:

•He said it was disappointing that the Raiders lost more games last season (13) than they did in 2013 (12) even though “there was more talent last year.” Asked if that was why there was essentially a whole new coaching staff, McKenzie said, “there was a whole lot that went into the 3-13 record.”

•Outside linebacker Sio Moore had “major” hip surgery following the season and is not expected to participate in offseason team workouts. McKenzie expects Moore to be ready for training camp.

•The Raiders will likely start the season with new starting cornerbacks for the fourth straight year. McKenzie expects Carlos Rogers and Tarell Brown — teammates for three years with the 49ers before joining the Raiders last season — to test the free-agent market.

“We like what our young corners have done,” McKenzie said. “I think veterans like that are here on the team to bring those young guys along.”

Third-year veteran DJ Hayden and second-year players TJ Carrie and Keith McGill are next up, and safety Brandian Ross has also showed he can play the slot corner position.

•The Raiders are unlikely to bring back running back Darren McFadden on a bargain-basement deal like they did last season. McFadden started off as the No. 2 back behind Maurice Jones-Drew, started 12 games and gained 534 yards on 155 carries (3.4 average) before giving way to Latavius Murray.

“To me, this year’s a little different because Latavius, in 2013 he spent the whole season rehabbing an injury,” McKenzie said. “Last year, I think he showed that he can be a player.”

Murray rushed for 424 yards in 2014, all but 11 coming in the season’s final six games.

•McKenzie, a former scout, loves this week and the combine.

“You make the phone calls, watch the tape and now all of the players are together in one setting,” he said. “It’s your first opportunity to talk to them, watch them, put them through the medical tests.

“A lot of information out there. It’s great.”

Vic Tafur is a San Francisco Chronicle staff writer. E-mail: vtafur@ sfchronicle.com Twitter: @VicTafur