The Saints will also be without both of their starting cornerbacks, Marshon Lattimore (hamstring) and Janoris Jenkins (shoulder), tight end Jared Cook (groin), guard Andrus Peat (ankle) and defensive end Marcus Davenport (elbow/toe).
Thomas, who has been sidelined with a high ankle sprain since Week 1, returned to practice this week and practiced on a limited basis every day. But the Saints apparently don't want to rush him back into game action. It's unclear whether he will be ready to play in Week 5, when the Saints host the Los Angeles Chargers on Monday Night Football. They have a bye in Week 6.
New Orleans' offense will certainly miss Thomas and Cook -- the latter left Sunday night's game with a groin injury and did not practice all week. The Saints already have struggled to find a consistent downfield passing game while losing back-to-back games for the first time since an 0-2 start in 2017.
The Saints rank last in the NFL with 283 yards by wide receivers this season and will continue to rely on newly signed veteran Emmanuel Sanders and third-year pro Tre'Quan Smith, among others, to help change that.
Drew Brees and Sanders finally started to find a rhythm together in Week 3, connecting on four passes for 56 yards and a touchdown. But Brees said, "I still think we can do a better job of getting the ball in his hands" and, "I think we're just scratching the surface."
Thomas, 27, has missed only one other game because of injury in his five-year career -- a foot injury during his rookie year in 2016.
The losses of Lattimore and Jenkins -- both of whom were added to the injury report during the practice week -- could prove just as daunting. The Saints (1-2) have allowed 35.5 points per game over the past two weeks -- the second-highest total in the NFL. And their opponents have now scored points on 13 of the past 16 drives, not including the end of a half or the end of a game.
The Saints rank 10th in the NFL in total defense, allowing 352.0 yards per game this year. And they rank 20th in passing yards allowed (252). But those totals don't include a whopping nine pass interference penalties against the New Orleans defense for 183 yards.
The Saints have experienced backup options in Patrick Robinson and P.J. Williams -- but both have been more effective in their careers as nickelbacks inside the slot. And Williams was actually shifted to safety this summer.
Payton said Friday that "I feel like we're deeper than we've been most years" at cornerback.
"We're doing good there," Payton said.
Other options include backup cornerback/special-teams ace Justin Hardee and veteran Ken Crawley -- a former Saints starter who was just re-signed to their practice squad this week after spending time with the Raiders and Cardinals this summer.