When the 49ers expect Brock Purdy to return from his toe injury

Purdy missed the 49ers' following two games, then returned for their Week 4 loss to the Jacksonville Jaguars. From the opening drive, it was clear that Purdy wasn't fit to play. His passes floated and were inaccurate, and his quickness was nonexistent. And in the process, he reinjured his toe. What a disaster.

This time, Purdy is taking three games off to be extra cautious. The 49ers want him to be close to 100 percent healthy when he returns so he doesn't reaggravate the injury like last time.

Purdy was a limited participant in practice all week, which means he's getting close to returning. If today's matchup with the Falcons were a must-win game, it's possible he might try to play.

But here's what the 49ers learned when he played through this injury against Jacksonville: Purdy isn't effective when he's injured. He needs to be close to 100 percent healthy to be him. Because quickness and mobility are such big aspects of his game, and he needs them to be successful. He also can't afford to lose any zip on his passes.

And that's why Mac Jones is starting tonight against the Falcons. Jones might not be better than Purdy when both of them are perfectly healthy, but Jones certainly seems to be more effective when injured. And that's because he's a pocket quarterback with a strong arm. He doesn't need an aggressive lower-body weight transfer to generate velocity with his arm. He can fling the football flatfooted if necessary.

It's worth noting that Purdy has now missed 7 of the 49ers' past 14 games due to injury, while Jones has missed just two games due to injury in his entire NFL career. Both of them are tough quarterbacks, but it's possible that Jones simply is more durable than Purdy, who has a slight build and holds the ball a long time. Jones is bigger than Purdy and gets rid of the ball much quicker.