SANTA CLARA, Calif. -- Before San Francisco 49ers safety Eric Reid returned from a knee injury two weeks ago against the Washington Redskins, he was asked if he believed he would plug back into his strong safety spot when he returned to full strength.

Reid expressed confidence that he would regain his job despite the emergence of Jaquiski Tartt, who had played well in Reid's stead. Against Washington, Reid didn't play much but was used in a sort of hybrid safety/linebacker role for the 10 snaps he did play on defense.

Sunday's game against Dallas offered Reid his first opportunity for a bigger workload since suffering the injury in Week 2 against Seattle. Upon his return, Reid found himself lining up at linebacker while Tartt remained in the strong safety spot when the Niners went to their nickel packages.

Eric Reid made three tackles from his new position at linebacker on Sunday. Ezra Shaw/Getty Images

"They told me that it’s the best move for the team, so I’m just embracing my new role and trying my hardest to be an impact [player]," Reid said. "I’m still playing, so I’m just trying to make an impact on the team, do the best I can to do that."

Against the Cowboys, Reid played 48 defensive snaps at his new position, finishing with three tackles and joining his defensive teammates in offering little resistance to a Dallas offense that posted 40 points and 501 yards.

After the game, Reid didn't sound like a player who was overly enthused about his new role, even though it's not a job that's significantly different than strong safety in coordinator Robert Saleh's 4-3 defensive scheme.

The Niners recently dealt with a couple of players -- linebacker NaVorro Bowman and running back Carlos Hyde -- publicly expressing their disappointment in changed and/or reduced roles. In discussing his new job, Reid didn't strike the same tone as Bowman, who was released after asking for a trade, largely because he still had a big role in the defense.

And Reid didn't feel the need to talk to 49ers coach Kyle Shanahan about the change. Shanahan explained his reasoning for moving Reid on Monday.

“I'm not concerned about that," Shanahan said. "If Eric wasn't happy with his role, I hope he'd come and talk to me about it. And we'd have a real good talk about that. But, we're asking, we're trying to get our best 11 guys on the field. And it's not just, it's not an absolute answer every week. It depends who we're playing, depends what personnel we want to go with, depends on some of the schemes we're going against. Eric's done a lot of good things in this league, has played at a high level, has done a real good job at safety.

"When you're playing eight-man front, the difference between safety and linebacker, it's just where you line up. But, you move from there a safety spot, too, just a little different depth. But, gap responsibility and everything are very similar on an eight-man front. I think Tartt's played at a very high level for us while Eric has been out, too. We're just trying to figure out the best way to get our best 11 out there."

Therein lies the difficulty for the Niners as they sort through their options defensively. In recent weeks, they have let go of Bowman and lost key contributors such as ends Arik Armstead and Tank Carradine to injury. What's left is a scenario in which three safeties -- Reid, Tartt and Jimmie Ward -- are clearly three of the best 11 defenders on the team.

Saleh's scheme already deploys the strong safety as a de facto linebacker, playing near the line of scrimmage on a consistent basis. But removing a bigger linebacker such as Ray-Ray Armstrong to add Reid, who said he has never played the position, means having another small body loading the run box.

"It’s a little different for me," Reid said. "I’ve never played the position. I tried to embrace it and learn as I go."

Going with smaller linebackers in sub-packages like the 213-pound Reid is not unique to the Niners as plenty of teams have had success with such a setup, but it didn't work too well against a bigger, more physical offensive line like Dallas'. Which means that how Reid is used moving forward could be a more fluid situation depending on matchups.

Still, it's worth noting how the Niners are using Reid and their decision to keep going with Tartt at strong safety. Reid is scheduled to become an unrestricted free agent after the season and though he looked like a natural fit at strong safety in Saleh's scheme, Tartt's performance earned him a longer look and could become a factor when the offseason arrives.

"Last week we thought we had an opportunity to get Eric at linebacker, which is really what he plays a lot when he's a down safety, which is every play except on third-and-long," Shanahan said. "And Eric, we put him in a position that we thought could help our team. I thought he played hard. I think he'll get better at it the more he does it. But, that isn't just set in stone that that's how we’re going to go week in, week out.”