When the Bears lost running back David Montgomery (knee) two weeks ago, many in Chicago fretted as he joined Tarik Cohen on the sideline. But Khalil Herbert and Damien Williams stepped up in those absences, as each player produced at least 75 scrimmage yards last week. Williams is now out with COVID-19, putting Herbert on the radar in the Week 6 Fantasy football rankings with the Packers coming to town.

Can you trust Herbert in his first start of the season? Where should he land among your Fantasy football picks? Before you lock in your lineups, be sure to check out the Week 6 Fantasy football rankings from the proven computer model at SportsLine. It can help you make those tough decisions on which players to start and which players to leave on the bench.

When it comes to ranking players, SportsLine's model beat human experts in Fantasy football for the past several seasons especially when there were big differences in ranking. Over the course of a season, that could literally be the difference between winning your league or going home empty-handed.

Last week, the model was extremely high on Ravens wide receiver Marquise Brown, saying he'd finish as a top-10 player at his position. The result: Brown hauled in nine receptions for 125 yards and two touchdowns against the Colts. Anybody who had him in their lineup was well on their way to a huge week.

Now, the model, which simulates every NFL game 10,000 times, has revealed its Fantasy football rankings for Week 6 of the 2021 NFL season. Head to SportsLine now to see them.

Top Week 6 Fantasy football picks 

One player the model is extremely high on this week: Bills tight end Dawson Knox. The third-year pro exploded in his last game with three grabs for 117 yards and a touchdown. The yardage blew Knox' previous career-high out the water, as it was his first game posting more than 67 receiving yards.

The tight end position has always taken a backseat in Buffalo's offense since Josh Allen became quarterback, but the team is making more of an effort to get the position involved. Knox is playing 77 percent of snaps, just behind Stefon Diggs' 79 percent and far past the 45 percent Knox played a year ago.

Knox should feast off a Titans defense that just allowed an 8-78-1 stat line last week to Jacksonville's group of uninspiring tight ends. The SportsLine model has Knox as a top five player at his position this week, making him a rock-solid TE1 in all formats.

And a massive shocker: Cowboys QB Dak Prescott, who's thrown three or more touchdown passes in each of his last three games, stumbles big-time and doesn't even crack the top 15 at his position. Prescott completed 68.8 percent of his passes for 302 yards and three touchdowns last week against the Giants. 

Prescott has already racked up 1,368 passing yards this season, but now he'll face-off against the Patriots, one of the NFL's stingiest defenses. The Patriots are giving up 317.6 yards per game on average to opposing offenses, which ranks fifth in the league. New England's defense also held Tom Brady, who leads the NFL in passing yards, to just 269 yards and zero touchdowns two weeks ago. With such a tough matchup on Sunday, Prescott is a player to consider putting on the bench in Week 6.

How to set your Week 6 Fantasy football rankings

The model is also calling for a surprising quarterback you aren't even thinking about to finish in the top 10 of its Fantasy football rankings. This pick could be the difference between winning big and going home with nothing. You can only see who it is here.

So who should you start and sit this week? And which surprising quarterback could lead you to victory? Visit SportsLine now to get Week 6 Fantasy football rankings for every position, plus see which QB is going to come out of nowhere to crack the top 10, all from the model that has out-performed experts big-time.