LAS VEGAS — Aaron Lynch is coming off his best game of the season and the 49ers are feeling it.
After losing their fifth straight to the Green Bay Packers on Sunday night, coach Jim Hackett was furious with his quarterback.
The 49ers (3-6) will get another opportunity to play without Lynch on Monday night when they face the St. Louis Rams (3:25 p.m.
Lynch is on injured reserve with a foot injury.
“I’m going to get to the bottom of it,” Hackett said.
“It’s something that I’m going on a mission to figure out.
It’s not just me.
It is Aaron and what he did.”
Aaron Lynch threw for 306 yards and two touchdowns as the 49th-ranked Bears won their fifth game in a row Sunday.
The Bears are now 5-0 and sit atop the NFC North with a three-game winning streak.
After failing to beat the New Orleans Saints, Chicago took a 3-2 lead with a 31-yard field goal from quarterback Zach Miller with 2:38 left in the fourth quarter.
But the 49er defense held on to hold the Bears to a field goal.
The Bears had a chance to tie the game on the ensuing kickoff, but the 49est Packers defense held them to field goals on a 4-yard pass to Kyle Rudolph.
The win moved the 49 at 2-2 on the season.
The Lions’ win gave them a three game winning streak and their longest since a seven-game run Nov. 24-Dec. 5, 2010.
The Lions are 10-0 against the Bears since the start of 2011.
Aaron Lynch was sacked four times and intercepted by the 49 on his way to his first career touchdown.
He completed 12 of 22 passes for 138 yards with two touchdowns and a pick.