The public got plenty of exposure to backup quarterbacks in Week 3 due to injuries and several massive blowouts. In some cases they played well -- Gardner Minshew was able to lead the Colts to an upset win over the Ravens, further advancing his legend status in the minds of some -- and in some they did not, including Blaine Gabbert coming on in relief of Patrick Mahomes in a 41-0 game, immediately throwing an interception, and then adding another for good measure.

Two QBs came out of Week 3 dealing with new injuries, and while neither has been ruled out for Week 4, it's important to know how those injuries affect the line.

Derek Carr suffered a sprained AC joint after landing hard on his shoulder while getting sacked, and while Saints coach Dennis Allen isn't ready to say he'll be unavailable to face the Buccaneers on Sunday, it seems unlikely he'll play. That sets Jameis Winston up for a "revenge game" against the team that once drafted him No. 1 overall; the last time he faced the Bucs, he threw three picks en route to a 20-10 loss in Week 2 last year and made it one more game as Saints starter.

Carr's old team, the Las Vegas Raiders, is also dealing with a QB injury as Jimmy Garoppolo is in the concussion protocol following his team's loss to the Steelers on Sunday night. Garoppolo completed the game, so it's unclear when he sustained his injury, but his absence would leave the Raiders in far dire straits than New Orleans as his direct backup is Brian Hoyer, who has played in a full game once since 2017. Rookie fourth-rounder Aidan O'Connell could be an option if Garoppolo can't go as well.

I share how much I believe a change at QB affects the line for all 32 teams as part of Mike Tierney's weekly QB rankings. As part of my Week 4 ATS power ratings, which you can find below, I'm operating as if Carr won't play but Garoppolo will. I'm also projecting the line for Rams-Colts as if Anthony Richardson will be back.

If you need a refresher on how to build spread power ratings, why they're important for beating the market and how successful I've been with this system at SportsLine, check out the Week 1 version of these power ratings. You can also check out SportsLine on Sunday afternoons as I give my initial power ratings adjustments for each team to get ahead of the market openers before diving in fully for this Tuesday feature. Otherwise, we'll jump right in.

Which lines are several points off their power rating projections for Week 4? And which teams are being undervalued by the market? ... Join SportsLine right now to see Week 4 power ratings from the expert who's 535-450-30 on ATS picks from 2017-22, returning $3,532 to $100 players!