The San Francisco 49ers are entering Week 3 with cautious optimism at the quarterback spot. Brock Purdy, with injury concerns, took part in practice this week, and although he wasn’t a full go, the latest update suggests he’s trending in the right direction.

Backup Mac Jones remains ready to go should Purdy be unable to start or finish. Purdy’s participation in practice reps has been encouraging: he’s moving better, taking snaps, and rejoining portions of the team drills several sources report. 

Mac Jones continues to stay sharp. While the expectation remains that Purdy will be under center, Jones’ presence provides the team with insurance. If Purdy’s timing, mobility, or ability to push the ball downfield are compromised due to his injuries, Jones can step in without the 49ers having to alter too drastically from their offensive identity.

Here’s what to keep an eye on with Purdy's status heading into the weekend:

What’s encouraging:

• Progress in practice: Purdy’s limited involvement in practice suggests that he’s feeling better. Even if he’s not back to full strength, the fact that he can throw, move, and participate in competitive settings boosts the confidence of coaches, teammates, and fans alike.
• Minimal downside with Jones: In Week 2, Mac Jones made his first start as a 49er. Jones performed well and completed 26 of 39 passes for 279 yards and three touchdowns to lead San Francisco to a 26-21 win over New Orleans on the road. Because Jones had that kind of week against the Saints, the transition if Jones plays again this week is much smoother.
• Offensive weapons ready to support: With playmakers around him who are also stepping up due to other offensive injuries, San Francisco has designed its system to help the quarterback succeed. Purdy’s mobility and decision making are keys, but having multiple options alleviates pressure on him having to do it all himself.

What could go wrong:

• If Purdy isn’t sharp: Even if Purdy plays, injury could hinder his accuracy, timing, or ability to buy time in the pocket. Mistimed throws and hesitation could lead to stalled drives or turnovers. That would force the offense to play more conservatively, reducing explosive plays, which would not be smart since explosive plays should actually be a key deciding factor in this week's game for the 49ers.
• Turnover risk rises: Limited mobility often causes quarterbacks to hold the ball too long or make riskier decisions. A compromised Purdy may lead to more pressured drop-backs or misreads. The exact kind of situations that lead to picks and sacks.

If Purdy can play at even 80-90 percent, the 49ers have a strong chance to continue their winning ways. But if he is limited enough to risk turnovers or bottle up the offense, then Mac Jones may need to carry the torch for another week. Either way, the 49ers can get it done this weekend, it’s just going to be a matter of how easily.