New Orleans Saints linebacker Jonathan Vilma is doubtful for Sunday's game against Houston with a left knee injury, coach Sean Payton said on Friday.
Vilma, who did not practice Friday, sat out the end of the first half of Sunday's victory over Chicago but returned to start the second half.
"Concern is, especially at that position with what he's doing, we want to see him close to 100 percent or at least at a percentage where he's comfortable enough," Payton said.
Payton also said that Vilma hadn't suffered a setback, only that he hadn't progressed as quickly as the team originally thought.
Fourth-year veteran Jo-Lonn Dunbar would replace Vilma.
Cornerback Tracy Porter (calf) was listed as questionable after practicing Friday on a limited basis.
For a full team-by-team breakdown of the league's latest injury news, check out NFL.com's Injury Report.
