By Jeff Joniak–

(CBS) The Bears (5-8) visit the Vikings (8-5) on Sunday for a noon game. Here are my keys to the game.

Offense: Starting faster

Every offense wants to start fast. The Bears’ first quarter scoring differential of -48 ranks 31st in the league, ahead of only the 49ers. With only two first-possession touchdowns and none on the first possession of the third quarter, the Bears are making it harder on themselves. They’re also given up the most first-quarter points in the league with 89.

As coach John Fox often reminds us, this edition of Bears has “little margin for error,” and without any scoreboard cushion, it just exacerbates the situation. The Bears have only scoring 32 third-quarter points, which is tied for the fewest in the NFL.

Minnesota’s defense has given up only one first-possession touchdown and an NFL-low 37 third-quarter points. Starting faster can create some Bears’ breathing room.

It’s worth noting that Vikings linebacker Anthony Barr and safety Harrison Smith are out Sunday.

Defense: Create turnovers

In 13 games, the Bears have forced only 12 fumbles, which is 26th in the league, while recovering, which is actually one off the league average. Fox feels the bulk of fumbles in the league come by way of the strip-sack of quarterbacks who are pressured and hit by defenders.

Bears linebackers Willie Young and Lamarr Houston are making a lot of noise right now rushing the passer and feeding off one another.  On top of that, the duo collected 18 combined tackles against the Redskins. They’re playing well and need that same production against Vikings quarterback Teddy Bridgewater and running back Adrian Peterson.

Minnesota has coughed it up 17 times but has lost only seven fumbles. Getting physical with this team and forcing the ball out or intercepting it is one of the biggest keys and needs for the Bears.

Special teams: Better be sound

This is another big test for the Bears coverage units. The Vikings lead the league in starting field position after kickoffs. They’re tied for third with 26 returns north of 20 yards and lead the NFL with five returns of 40 yards or more. Cordarrelle Patterson leads the NFL in kickoff return average at 31.1 yards.

They also own a punt return touchdown by Marcus Sherels against the Bears and four returns of 20-plus yards.

Vikings kicker Blair Walsh has two game-tying or game-winning field goal attempts that he made, including one that beat the Bears. He’s collected 100 points but has missed three extra points and five field goals.

Bears kicker Robbie Gould has missed six of his last 15 field goal attempts, so his slump is something that needs to be considered in this game. He’s been wide left on four of his five misses.

Both kickers have 26 made field goals.

Intangibles: Spoil the stew

It’s time again for the Bears to spoil the stew. Making a playoff push, the Vikings feel they are in position to take down the Bears this week and the 6-7 New York Giants next week before a showdown game against the Green Bay Packers at Lambeau Field.

The Bears can ruin the plan with a spirited, competitive and complete effort. The Vikings are banged up a bit, and while the Bears aren’t exactly injury-free, they’ve learned how to play without many different players and leaders. The Bears need to have better execution with their high red-zone offense and their 10-play drives.

Chicago is 27th in passing inside the 30-yard line, with only 13 passing touchdowns, which ranks 24th. The Bears are 19th in 10-play touchdown efficiency despite being fourth in number of 10-play drives, with 26 and only nine touchdowns. The Vikings struggle inside the 30-yard line, scoring only 176 points, which is 29th.

Jeff Joniak is the play-by-play announcer for the Bears broadcasts on WBBM Newsradio 780. Follow him on Twitter @JeffJoniak.