Jennings (hip) isn't practicing Friday, Nick Wagoner of ESPN.com reports.
Rookie first-round pick Ricky Pearsall (chest) has a shot to make his NFL regular-season debut, but the 49ers probably will favor veteran Chris Conley in the No. 3 receiver role if Jennings doesn't play this Sunday against the Chiefs. A third straight missed practice has Jennings trending toward his first absence of the season.