Penny (calf) is listed as doubtful for Sunday's game against the Titans, John Boyle of the Seahawks' official site reports.
Since Penny hurt his calf Week 1 at Indianapolis, the injury has transformed from minor to one that's expected to sideline him for a few weeks. With a doubtful designation for Sunday, he's almost certainly going to be listed among the Seattle's inactives, which would give Alex Collins, DeeJay Dallas and Travis Homer a chance to make an impact in the ground game behind starter Chris Carson.