Two keys for Bears vs. Rams: Mitch Trubisky starting — and finishing

Rams defensive tackle Aaron Donald is on a tear — 12½ sacks, 24 quarterback hits and four forced fumbles in his last six games. He’s on pace to win his second consecutive Defensive Player of the Year Award and is even being mentioned as a league MVP candidate.

But in that span, the Rams’ defense has allowed 391 yards per game (25th in the NFL) and 28.8 points per game (30th). Even considering they’ve faced three of the highest-scoring teams in the league — the Saints, Chiefs and Seahawks — that’s still a lot of points for a defense with such a devastating player on it.

Therein lies the opportunity and risk for Bears quarterback Mitch Trubisky if he starts as expected Sunday night against the 11-1 Rams at Soldier Field. The opportunity for points is evident — the Bears might not be the Saints or Chiefs, but they’re still 10th in the NFL in offensive points scored (25.1 average) — ninth in the league in games that Trubisky has started (25.8).

But if the risk of injury is great in any game in the NFL, it’s doubly so in this one — with Donald on the field and Trubisky recovering from a sprained shoulder that forced him to miss the Bears’ last two games. The question not only is whether Trubisky will start, but whether he’ll finish. If Trubisky’s pain tolerance is in doubt Wednesday, can he take a hit from Donald on Sunday?

“That’s part of football,” coach Matt Nagy said Wednesday before practice. “That comes into play. Those are the questions that you ask yourself — us as an organization. The pain is one thing. It’s the health, as well. We’ve got to make sure the combination of pain and making sure that nothing either gets reinjured or worse is what we want to make sure we take care of.”

Nagy has been careful about injured players, but he throws caution to the wind once the game starts — boldly putting Chase Daniel in harm’s way as a pass receiver on a gadget play against the Lions on Thanksgiving. So there’s little doubt that Nagy will let it all hang out against the Rams if Trubisky starts. That’s their best chance to beat the Rams.

But Donald’s presence — and the sudden, blind-side opportunities for other Rams defenders that his pressure creates — is going to force Trubisky to be a little more careful than he has been. And he knows it.

RELATED

• Keeping Mitch clean: Bears rookie James Daniels braces for test in Aaron Donald

• Bears winning, Packers crumbling: What’s the name of this strange world?

“The first thing is we need good ball security,” Trubisky said. “And that’s in the pocket — just keeping my eyes downfield, moving up . . . not get rattled and move in between. And then knowing when to use my legs and knowing when to get the ball out. So you’ve got to have that internal clock this week — not holding on to the ball too long.”

With Donald and Ndamukong Suh inside, Trubisky’s mobility figures to be a must. After getting injured on a run against the Vikings, the only limitation on his running game is to avoid being reckless — a line he has come close to crossing this season.

“Just being smart,” Trubisky said. “Trying to slide properly. Trying not to be so unorthodox. Picking up yardage and then getting down when I need to get down. Getting out of bounds. And continue to stay aggressive.”

The challenge for Trubisky against the Rams is the same as it has been in every game in this developmental stage in his second season — approaching the line without crossing it.

“I’m not going to go out there if I’m not 100 percent,” Trubisky said. “I’m going to play my game. No reservations. Just go out there and do what I know how to do.”