Wide receivers Driver, Crabtree nursing injuries

Here's a few fantasy updates:

Green Bay Packers wide receiver Donald Driver is nicked up. He missed his fifth straight practice Thursday with a calf injury. Driver is not expected to play in the team's first preseason game this weekend. If healthy, Driver is a No. 3 or 4 fantasy receiver.ed

Chris Chambers is ahead of rookie Dexter McCluster for the No. 2 receiver spot in Kansas City while Dwayne Bowe is entrenched as the top starter. Unless the talented McCluster can bypass Chambers, he has little fantasy value this season.

Chiefs head coach Todd Haley has listed Thomas Jones as the primary ball carrier and Jamaal Charles as the back-up on the team's initial depth chart. Apparently Jones has been getting most of the first-team snaps in practices, as well. Haley said both backs will see enough work to keep them happy. It sounds like a running-back-by-committee (RBBC) for the Chiefs. That makes both players No. 2 fantasy backs at best. Stay tuned.

If you're high on San Francisco wideout Michael Crabtree this year, you better take a second look. Crabtree dropped the first two passes thrown his way on Wednesday before leaving the workout with a neck strain. Unless he improves, he's at best a No. 3 fantasy receiver.

It looks like there's a pretty tight battle for the No. 1 running back spot with the New York Giants. Ahmad Bradshaw has been doing a lot of work with the first team and Brandon Jacobs has looked faster this year after offseason surgery. If there's RBBC, the winner of the competition should have value as a low-end No. 2 running back.

The preseason began in earnest Friday night with a full slate of games. I'll report back after the weekend to assess whose fantasy value took a hit and who got a boost.

Don't forget to check out my Fantasy Forum in Tuesday's print edition. This week I'll be writing about sleepers and undervalued players heading into the season.