Danny Trevathan took another step in his recovery from a calf injury, practicing without restrictions Thursday after being limited Wednesday.

Trevathan has missed the last three games with the injury he sustained Oct. 29 in a loss to the Saints. The Bears are hoping that Trevathan will be able to play Sunday when they host the 49ers.

“I thought Danny was playing really well those 4-5 weeks before he got hurt,” said defensive coordinator Vic Fangio. “Before he got hurt he was playing at a very, very high level. If he can come back at that level, that would be a bonus.”

Trevathan led the Bears with 52 tackles at the time of his injury and now ranks fourth behind Christian Jones (69), Adrian Amos (53) and Kyle Fuller (53). The Bears are 3-4 with Trevathan in their lineup and 0-4 in games he’s missed this season.

In his last five contests, Trevathan has registered 46 tackles, two pass breakups, one fumble recovery and three tackles-for-loss.

“Anytime you have a starter out it can be problematic, but the rest of the players have to carry the load,” said coach John Fox. “It would be good to potentially have him back this week.”

Thin spot: Injuries have depleted the Bears at safety, with Amos (hamstring), Deon Bush (ankle) and DeAndre Houston-Carson (ankle) all unable to practice Thursday. The only healthy safety who played in last Sunday’s loss to the Eagles is Eddie Jackson.

There were new albeit familiar faces at the position Thursday, however. Veteran Quintin Demps practiced for the first time after spending the last nine weeks on injured reserve with a broken arm he sustained in a Week 3 loss to the Steelers. And veteran Chris Prosinski also practiced after rejoining the Bears earlier in the day.

Asked about the safety tandem he’d like to see Sunday, Fangio said: “It’s up in the air right now. We have a bunch of guys that are hobbled and not sure of their status yet. Not really sure how that will shake itself out yet.”

The Bears have 21 days to decide whether to add Demps to the 53-man roster. Given his long layoff, it’s unclear whether he’d be ready to play Sunday against the 49ers.

“That’s something we’re evaluating today,” Fox said. “Today was his first practice back. We haven’t met as a staff after practice. But those are all options. We got a couple guys nicked yesterday in practice, one safety (Bush) and a linebacker (Isaiah Irving), so we’re just covering to see what we need to have active for Sunday’s game against San Francisco.”

One more option: Another player working at safety is Deiondre’ Hall, who was switched to the position from cornerback during the offseason but has not played this year.

The 2016 fourth-round draft pick returned to practice last Wednesday for the first time since opening the season on injured reserve with a hamstring injury he sustained in the preseason finale.

“He’s a talented guy,” Fox said. “He’s got good ball skills. I think he has played both positions at corner and safety. He’s probably not as well-oiled both from an experience standpoint and reps at the safety position. But we’re looking at him, evaluating. Our DB coaches are doing a good job meeting with him extra. We’ll kind of see where we are by the end of the week.”

“The guy hasn’t had a lot of practice time at safety,” Fangio added. “In training camp he was spending time at corner, some at safety, and then he got hurt and hadn’t done anything until I believe last week when we let him start practicing. So he has not had a lot of prep for it. I’m interested to see where he is mentally.”

Reunion time: Outside linebacker Lamarr Houston, claimed by the Bears off waivers Wednesday from the Texans, practiced for the first time Thursday. Houston spent the last three seasons with the Bears before being released Sept. 6 after he hurt his knee in the preseason finale.

Houston has rejoined the Bears less than two weeks after second-year outside linebacker Leonard Floyd suffered a season-ending knee injury in a loss to the Lions.

“[Houston] adds some football experience to that group,” Fox said. “We were light since losing Leonard, so he became available and we snatched him up. I think the guys were excited to see him and he was excited to get back.”