Bears safety Quintin Demps breaks his left forearm

Bears safety Quintin Demps broke his forearm Sunday. (AP)

The first time the Bears lost a defensive captain to injury, they promoted the runner-up in team voting to the leadership position.

Now they’ll need to find the second runner-up.

Safety Quintin Demps suffered a broken left forearm in the Bears’ victory Sunday against the Steelers. Coach John Fox was unsure Monday whether Demps would go on injured reserve, but his absence figures to be significant — at least a month — nonetheless.

Adrian Amos, who started 30 games in his first two seasons but failed to intercept a pass, will take Demps’ place. Amos’ lack of production led the Bears to give Demps a three-year, $13.5 million deal during the offseason and to draft safety Eddie Jackson in the fourth round.

‘‘Everybody in the league deals with injuries; we’re no different in that aspect,’’ Fox said. ‘‘You’d like to see that stop at some point.’’

The Bears have lost a defensive starter in each of their first three games: inside linebacker Jerrell Freeman in Week 1, inside linebacker Nick Kwiatkoski in Week 2 and Demps in Week 3. Freeman and Demps started the season as captains, and defensive end Akiem Hicks has inherited Freeman’s role.

‘‘If losing a player is going to make you down in the dumps, then the NFL isn’t the place for you,’’ guard Kyle Long said. ‘‘One thing we’re no stranger to is injury. And as football players, it comes as no surprise that people go down every week.

‘‘Obviously, Q’s going to be somebody we’re going to miss having for a few weeks. But I really think we have the guys who can step up and go. And that’s what separates this team from previous teams we’ve had.’’

That remains to be seen, but this defensive unit already might be better than any in the post-Lovie Smith era. Consider that three of the six touchdowns the Bears’ defense has allowed this season have come on drives of 35 yards or fewer because of turnovers by the offense.

The Bears’ defense gave up 23 points in Week 1 to a Falcons team that has averaged 32 points since. The Steelers scored 17 points after averaging 23.5 points in their first two games.

Cornerback Sherrick McManis said Amos is a ‘‘better player, smarter player’’ in his third season, but communication will be key. Demps and Jackson have been teamed together since the Bears’ third preseason game.

‘‘That’s a key with Quintin,’’ Fox said. ‘‘It’s very helpful that he’s been there a lot, even though the system is more new to him that it is to Adrian Amos.’’

Amos replaced Demps after he broke his arm while tackling Steelers running back Le’Veon Bell in the fourth quarter.

‘‘Hopefully it’s not an every-game thing,’’ McManis said. ‘‘They put this team together to have quality backups for guys to get the job done, so it’s a next-man-up mentality and it’s kind of how our team functions. I think we’ll be fine.’’

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Email: pfinley@suntimes.com