Brock Purdy‘s return to practice this week inspired some hope that he could suit up for the 49ers in Week 3, but head coach Kyle Shanahan said (via Matt Barrows of The Athletic) that it is “highly unlikely” he starts on Sunday. Instead, it will be Mac Jones under center in San Francisco against the Cardinals. 
Purdy missed Week 2 due to injuries to his toe and shoulder. The shoulder issue no longer seems to be preventing him from playing, but the fourth-year quarterback practiced in a limited capacity for the last three days as the toe continued to ail him. His comments on Thursday suggested that he could be a game-time decision, depending on how he feels on Sunday.
Instead, it appears that decision will be made on Saturday, when the team is required to make roster decisions like inactives and practice squad elevations. Shanahan indicated that Purdy could still be active as the team’s second- or third-string quarterback, according to NFL Network’s Tom Pelissero. Pelissero’s partner at NFL Network, Ian Rapoport, expanded on that topic, explaining that, while a QB2 role may be a possibility, a QB3 role as a break-glass-in-case-of-emergency option makes far more sense.
If it’s determined tomorrow that Purdy can’t go or that he can only suit up as an emergency quarterback, practice squad passer Adrian Martinez will, once again, be called on to back up Jones. How they do that will be determined by Purdy’s situation. If Purdy is unable to suit up, Martinez would simply need to be designated a standard gameday practice squad elevation as he was last week. If Purdy suits up with the intention to serve in an emergency role, Martinez would need to be signed to the 53-man roster, since emergency third quarterbacks need to be on the active roster.
In other injury news, two rookies were injured in practice yesterday, per Barrows. While seventh-round guard Connor Colby is only listed as questionable with a groin injury, fourth-round wide receiver Jordan Watkins is reportedly a candidate for injured reserve with a calf injury.
Ely Allen contributed to this post.
Mac Jones to start last week’s game? Check your headline.
Just get Doc & Marty, fire up the Delorian, he can start in week two.