NEW ORLEANS -- Drew Brees was sidelined by a rib injury throughout the second half of the New Orleans Saints' 27-13 victory over the San Francisco 49ers on Sunday, with Jameis Winston taking most of the snaps in his place.

Coach Sean Payton said Brees will get an MRI and X-rays to determine the extent of his injury. But he said Brees let him know he didn't think he could "function in the second half" after the injury and didn't feel better through the halftime break.

"He took a heavy shot in the first half. As he came out in the second half, he felt it was really impacting him," Payton said. "His back felt sore as he tried to throw. He just came up to me and said, 'Hey, I don't feel I'm capable of playing.' And so quickly we made the switch, and that happens sometimes.

"He felt strong enough about letting me know. And I know when he does that -- which is probably gonna be the first time in 15 years that it was significant enough that he felt like he couldn't function in the second half."

The Saints (7-2) secured their sixth consecutive victory despite Brees' absence. He did play through the injury in the final minutes of the first half -- then remained in uniform while watching from the sideline in the second half.

Winston, who was appearing in just his second game of the season as New Orleans' backup, showed some rust while completing 6 of 10 passes for 63 yards with zero touchdowns. But he also wound up with zero turnovers despite one close call. And he helped set up one TD with a 3-yard run to the 1-yard line.

The Saints' other backup QB, Taysom Hill, also took control of one drive, running the ball four times for 30 yards. But he lost a fumble on his fourth attempt.

New Orleans' defense and special teams played even bigger roles in the victory. Defensive backs Malcolm Jenkins and Patrick Robinson each intercepted passes, and undrafted rookie receiver Marquez Callaway recovered two fumbled punt returns.

Brees appeared to be injured while absorbing a big hit by defensive tackle Kentavius Street with 8 minutes, 20 seconds remaining in the second quarter, which resulted in a questionable personal-foul penalty against Street.

Hill took the next two snaps at quarterback after that play while Brees showed obvious discomfort on the field. Brees lined up at receiver on the first play -- then went to the sideline for one play to throw the ball and try to get loose.

Brees reentered the game to pitch the ball to running back Alvin Kamara for a 2-yard touchdown. Then he played the next series, completing five passes on another touchdown drive.

Brees, 41, has also been limited in practice the past two weeks because of an injury to his right throwing shoulder. However, he has missed only six games because of injury in his 20-year NFL career -- five of them in 2019 because of a torn thumb ligament.

Kamara scored all three of the Saints' touchdowns on Sunday, continuing to make his case as the NFL's Offensive Player of the Year, if not an MVP candidate.

The Saints suffered a number of injuries in Sunday's clunky performance -- which was a bit of a letdown from their huge 38-3 victory at Tampa Bay a week earlier.

Cornerback Marshon Lattimore left early with an oblique injury, though he also remained dressed on the sideline. Safety C.J. Gardner-Johnson left the field late in the game with an unspecified injury, though he also looked prepared to reenter the game. Receiver Tre'Quan Smith and tight end Josh Hill were ruled out with concussions. And offensive linemen Terron Armstead and Andrus Peat both briefly left the field with injuries before returning.