Charvarius Ward has a muscle strain and will miss a couple of weeks

Kyle’s update, 10:20 AM PT: The 49ers announced the signing of CB Ken Crawley to a one-year deal and waived/injured S Leon O’Neal Jr., who struggled when he was on the field.

Crawley appeared in three games with the Saints last season and four with New Orleans the previous season. The 29-year-old has started 25 games in his career and provides a veteran in a secondary full of youth.

49ers head coach Kyle Shanahan was on KNBR Wednesday morning talking about the plan for the preseason and injury updates.

The big one is cornerback Charvarius Ward, who will miss a couple of weeks due to a muscle strain. So if I’m the 49ers, I’m shutting Ward down until Week 1, along with Emmanuel Moseley.

I know what I have in those two, let the first and second-year cornerbacks get much-needed reps during the preseason while the starters heal.

Shanahan said right tackle Mike McGlinchey will play “a little bit.” I’d expect to see the 49ers' offense get 15-20 plays, depending on the success of each drive.

If they go out and score on a 10-play drive, shut it down. If the offense goes three-and-out, send them back out.

Shanahan provided some good news as he believes Arik Armstead has a chance to return to practice next week when the team travels to Minneapolis for joint practices against the Vikings.

The preseason is tricky because game reps matter, and you want your guys to get in shape, but the risk significantly outweighs the reward. So, whether it’s Armstead, McGlinchey, Ward, Moseley, or Javon Kinlaw, the Niners would be wise to be careful with their core players.