If Winston can't go, backup quarterback Andy Dalton would replace him, marking the third time Dalton would start a game in London -- including a 27-27 tie against Washington and current Vikings quarterback Kirk Cousins in 2016 -- and his first regular-season start for the Saints.
"I think it's doubtful that Jameis plays in the game, so our plan right now is to have Andy ready to go," Saints coach Dennis Allen said Friday. "We'll see how things go overnight, but Andy will be ready to go if that's the direction that we go."
Wide receiver Jarvis Landry (ankle), who was also injured in that game, is questionable to play, as is running back Alvin Kamara (rib). That could mean more targets for rookie Chris Olave, who was named the NFC Offensive Rookie of the Month for September.
Winston missed all three of the Saints' practice sessions at the Hazelwood Centre in Sunbury-on-Thames. The quarterback has been dealing with a number of injuries since the preseason, with a transverse fracture in his back being the biggest issue.
"I just think it's just a little bit of the accumulation of the wear and tear," Allen said. "It's a long season, and I don't think his body responded quite the way he anticipated over the first couple of days. So yeah, we've rested him this week and we've still got a couple of days, but we'll see."
Allen described Winston as a "little frustrated" that he didn't physically feel better as the week went on. Allen said Winston usually feels the worst at the beginning of the week before recovering closer to the game, but that didn't happen this week.
"He's a fighter, he's a competitor, he wants to play," Allen said.
Winston and the offense have struggled to get off to a fast start this season, with the back injury complicating things.
Allen said starting Dalton would not be because of performance, but for medical reasons only.
"You look at this as a long season. You don't want to just continue down the same circular path each and every week," Allen said. "I think part of this week and missing practice this week was a lot about trying to get the rehab and get him healthy."
Dalton signed a one-year, $3 million deal in free agency while Winston was rehabbing a torn ACL. Adding Dalton was part of an effort by the Saints to fix the backup quarterback situation after they started Winston, Taysom Hill, Trevor Siemian and Ian Book last season because of injuries and COVID-19.
"I've been in this situation before where you're the backup and have to step in and play, and I've also played in a ton of games and started a ton of games," Dalton said. "My experience, I know how to handle the whole process of everything. If my number is called ... I'll be ready."
Hill, who was moved to tight end this season, took snaps backing up Dalton in practice this week, although Allen said they had always intended to still give Hill some snaps at quarterback.
Dalton was the starting quarterback for the Cincinnati Bengals for the better part of nine seasons (2011-19). He started nine games as a backup for the Dallas Cowboys in 2020 and six games as a backup for the Chicago Bears last season.
"Look, Andy's done this," Allen said. "He's performed at a high level in our league, and that's really one of the big reasons why we brought him here. In case he's called upon, we feel highly confident that he can go in and do the job. We're kind of looking in that direction, and again, we'll kind of take it to the last minute."
Dalton took a significant number of first-team snaps early in the offseason as Winston recovered from his ACL tear and again during training camp practices when Winston injured his foot. Dalton was a combined 10-for-10 for 124 yards and a touchdown in two preseason games.
"I had the whole spring while Jameis was rehabbing," Dalton said. "And I think that was a great time for me to get to know these guys and be around them. Just some of the stuff we've done through camp and everything, I feel really good about where we're at."