According to Dave Birkett, eight total players (not counting the two on the PUP list) have already been ruled out for the preseason opener against the Steelers tomorrow.
In addition to Louis Delmas, who was ruled out on Thursday, these players will not play tomorrow: RB Kevin Smith, WR Mike Moore, TE Brandon Pettigrew, DE Jared DeVries, LB DeAndre Levy, CB Aaron Berry and K Jason Hanson.
The two names that jump out the most to me are Smith and Pettigrew. Both have been practicing, but apparently they are not quite ready to play in an actual game just yet. I thought we would see Smith simply because he has seemingly been so far ahead of schedule, but it's obvious the coaches don't want to rush him back.
As for the other players that are out, there are no real surprises. Moore, DeVries and Levy have been out for an extended period of time, and Hanson is coming off knee surgery and likely won't play until the regular season. Berry has been out for a good period of time now as well with an injury that appears to be of the week-to-week variety rather than day-to-day, so again, no surprise there.