Trust me: Backing Mac Jones is a concerning practice, and the 49ers are certainly on the low side of the quarterback battle. Kyle Shannahan's goal will be ensuring San Francisco does not get behind the sticks that way Jones can keep his volume down. Kyler Murray remains limited as a passer, so Nick Bosa & Co. keeping him in the pocket will be key. The Cardinals' injured secondary should provide some open windows. Meager spread at home for a team with the better defense and coach.

Kyler Murray has shown a willingness to run early in the season, rushing seven times in each game for a total of 70 yards. Based on the 49ers' defensive scheme, this should be another good matchup for Murray on the ground. While I like the 49ers to win, I also bet Murray to go Over his rushing prop.

Brock Purdy's availability seems doubtful for the Niners, who won at New Orleans last week with Mac Jones taking snaps. Late word has Jones making the start on Sunday. Regardless, San Francisco has a bit of a makeshift look about it, still minus receiving weapons Brandon Aiyuk and George Kittle, while Christian McCaffrey's contributions have been a bit muffled in the first two weeks as the Niners escaped with a couple of road wins. In this unlikely NFC West showdown, the Cards are also 2-0, and have been playing good football since before the midway point last season, standing 8-5 their last 13 games. Kyler Murray's dual threat also led the Big Red to a pair of wins over the Niners last season. Play Cardinals

The 49ers have won and covered their first two games of the season, but they come into this game with Mac Jones expected as their starting QB, as Brock Purdy has turf toe. The Cardinals are also 2-0 on the season, but they played two of the worst teams in the NFL, the Saints and Panthers. They looked sketchy at best, but there was enough good play to have me betting them this week. They swept the 49ers last season, and the receivers aren't the same without Deebo Samuel, Brandon Aiyuk, and possibly Jauan Jennings, who didn't practice on Wednesday. George Kittle is also out. The betting move in this game is to pay an extra 8 cents to get +3 -118 on Arizona.

There's a chance Brock Purdy can play but even if he can't I'm OK with rolling Mac Jones here. It's wild that Mac played as well as he did and it's still a 1.5-point upgrade in some spots from Mac to Purdy when Kyle Shanahan announced Purdy would practice some on Wednesday. Even if Purdy ends up not playing we'll have to wait until Sunday to get a reasonable ML option and the Cardinals secondary is banged up I'm willing to buy in now.

Brock Purdy (toe) isn't expected to play, but the Cardinals' injuries might be more impactful. Arizona lost its top three corners -- Max Melton, Garrett Williams and Will Johnson -- during the 27-22 win over Carolina, and early indications are none will be ready for Week 3. That bodes well for Mac Jones, who looked very comfortable running Kyle Shanahan's offense. He threw for 279 yards and three touchdowns with no interceptions at New Orleans. Back the 49ers in their home opener.