WHAT TO WATCH 4

Key matchup

Patriots quarterback Tom Brady hasn’t been quite as prolific as usual this season — he’s 12th in passer rating (98.2), 17th in passing yards (1,599), 18th in yards per attempt (7.5) and tied for sixth in touchdowns (13). But he’s a maestro when it comes to running the Patriots’ offense, which has scored 38, 38 and 43 points in its last three games — victories over the Dolphins, Colts and Chiefs.

It remains to be seen if Bears linebacker Khalil Mack will play or how effective he’ll be if he does play after practicing only Friday while recovering from a sprained right ankle. But the Patriots might be short-handed, as well. Tight end Rob Gronkowski (back/ankle) did not travel with the team to Chicago, has been downgraded from questionable to doubtful and is “highly unlikely” to play, according to ESPN’s Adam Schefter. Gronkowski has 26 receptions for 405 yards (15.6yard average) and one touchdown this season, including three catches for 97 yards against the Chiefs last week.

The Patriots’ offense suffers without Gronkowski but isn’t debilitated. In two games without him last year, Brady had a 59.5 passer rating in a 27-20 loss to the Dolphins and a 94.1 rating in a 19-14 victory over the Buccaneers.

Trending

With quarterback Mitch Trubisky and the Bears’ offense showing significant signs of growth, the Bears have jumped from 26th to 19th in total offense and from 18th to 10th in points scored in the last three weeks. Trubisky threw nine touchdown passes and one interception against the Buccaneers and Dolphins and ranks seventh in the NFL in passer rating (105.6).

Player to watch

Bears wide receiver Taylor Gabriel is quickly developing a rapport with Trubisky. The 5-8, 165-pound Gabriel has had back-to-back 100-yard games — seven catches for 104 yards and two touchdowns against the Bucs and five catches for 110 yards against the Dolphins. He did not have a 100-yard receiving game in four seasons with the Browns and Falcons.

The Patriots’ defense is known for neutralizing threats like that. It remains to be seen if the Bears’ offense is mature enough to make the Patriots pay if they do that.

X-factor

The Bears could have had a four-game winning streak but instead are coming off a disappointing 31-28 overtime loss to the Dolphins. They responded to a similarly disappointing loss to the Packers in Week 1 with a victory over the Seahawks. But the Patriots present a greater challenge mentally and physically. The Bears are going to have to take a big step forward to respond here.