Packers at Bears — What to watch for

WHEN THE BEARS HAVE THE BALL

After three weeks of regression, there’s a sense of anticipation as Thomas Brown takes over for Shane Waldron as offensive coordinator. Brown can’t change too much in midstream, but a ‘‘fresh perspective,’’ as tight end Cole Kmet called it, might make a difference.

Rookie quarterback Caleb Williams, who has a 64.7 passer rating and a 50.5% completion rate in the last three games after posting a 122.8 rating and a 74.1% completion rate during the Bears’ three-game winning streak, is obviously the biggest potential beneficiary.

In Brown’s debut as a play-caller for the Panthers in Week 7 of last season, Bryce Young had a season-best passer rating (103.6, with a 71% completion rate, despite six sacks) in a 15-12 victory against the Texans. Also noteworthy: A Panthers offense that averaged 10.6 points in the last 11 games last season scored 30 against the Packers with Brown calling plays.

Two areas of focus: the first quarter and third-down conversions. The Bears have scored 10 points in the first quarter this season, the fewest in the league, and are 31st in the NFL in third-down conversions after going 1-for-14 last Sunday against the Patriots.

The Bears’ offensive line against the Packers’ defensive front will be the key matchup, especially after Williams was sacked nine times against the Patriots. Starting tackles Braxton Jones and Darnell Wright will return after sitting out last week with injuries, but left guard Teven Jenkins is out, with Ryan Bates starting for him. The Packers rank 14th in sacks and 10th in rushing defense.

WHEN THE PACKERS HAVE THE BALL

A Bears defense that inexplicably has plummeted from first in the NFL against the run last season to 24th this season (133 yards per game), even though it has improved from 20th to seventh in scoring, faces a major challenge against a Packers rushing offense that ranks third in the NFL (154.8 yards per game).

Running back Josh Jacobs is averaging six yards per carry in his last three games (50 carries, 298 yards, two touchdowns), including 25 carries for 127 yards and two touchdowns against the Jaguars and 13 carries for 95 yards against the Lions in his last two.

‘‘This offense starts with Jacobs. He looks quicker and faster this year,’’ Bears defensive coordinator Eric Washington said. ‘‘They do a nice job of opening holes for him, and his ability to be downhill really sets up the play-action with [quarterback] Jordan Love.’’

That’s the challenge for the Bears’ defense, which brought out the best in Love last season — a 129.3 passer rating with five touchdowns and no interceptions in two games.

In Week 17 of last season — when the Bears were playing without cornerback Jaylon Johnson — Love completed 27 of 32 passes for 316 yards and two touchdowns for a career-best 128.6 rating.

Love has been hot-and-cold this season, with 15 touchdowns and 10 interceptions in seven games after throwing 11 picks in 17 games last season. He has a 71.0 passer rating in his last two games (no touchdowns, two interceptions).