Lamb sat out Wednesday's practice with a foot laceration that isn't considered serious, Mike Garafolo of NFL Network reports.
Lamb was an observer at Wednesday's practice and is expected to sit out Thursday's session, too, meaning that he's unlikely to suit up in Saturday's preseason game against the Chargers. The foot issue isn't anything that should keep him off the field for long, and he'll enter Week 1 as Dallas' unquestioned No. 1 receiver with Amari Cooper now in Cleveland and with Michael Gallup (knee) working his way back from an ACL tear.