METAIRIE, La. -- Drew Brees will return to the New Orleans Saints' starting lineup in time for Sunday's marquee matchup against Patrick Mahomes and the Kansas City Chiefs, a source told ESPN's Adam Schefter.

The Saints believe Brees is fully healthy and doctors have cleared him to play, the source told Schefter.

It will be the first meeting between the two elite quarterbacks as their teams angle for the No. 1 seed in their respective conferences.

Brees, 41, returned to practice this week after missing four games because of 11 broken ribs and a punctured lung. Saints coach Sean Payton insisted that Brees would not be rushed back into the lineup and that he would need to "be asymptomatic, feeling good, strong and like he can function and be an asset and play well." Brees apparently met the standard he needed to reach.

"There's a recovery element, there's a strength element. And I'll know when that time comes," Brees said in his most recent media interview with Cox Sports Television on Sunday night.

The Saints (10-3) went 3-1 in Brees' absence with Taysom Hill as their starting quarterback. They suffered a 24-21 loss at Philadelphia last week, which currently leaves them in line for the No. 2 seed in the NFC. (The 10-3 Green Bay Packers hold a head-to-head tiebreaker.)

With Brees back in the starting lineup, Jameis Winston will continue to be the Saints' No. 2 quarterback, with Hill playing his jack-of-all trades role, including some plays at QB, a source told Schefter.

Meanwhile, Saints wide receiver Michael Thomas' status for Sunday remains uncertain after he did not practice Wednesday or Thursday because of a lingering ankle injury. Thomas has played through the injury since returning to the lineup in Week 9 but has missed more practice time than usual this week.

Brees has always taken pride in trying to beat the doctors' projected timetables when it comes to recovering from injuries. But he could have even more incentive than usual in this, his 20th season, since it might be his last.

Although Brees has never made any announcement about when he plans to retire, sources have told Schefter that he is expected to do so after this season. Payton has also hinted that the Saints are preparing for that possibility when talking about the team's long-term quarterback outlook. Brees already has a post-playing career lined up as an analyst for NBC.

Until last year, Brees had missed only one game in his NFL career due to injury. But he missed five games in 2019 because of a torn ligament in his thumb and four more games this year.

Brees suffered the punctured lung and some of the broken ribs during a Week 10 win over the San Francisco 49ers. He played the final eight minutes of the first half -- and completed two touchdown drives -- before he was unable to keep playing after halftime.

Doctors believe the rest of his broken ribs occurred a week earlier in the Saints' Week 9 win at Tampa Bay.

Although Brees faced scrutiny over his lack of downfield throws early this season, he and the Saints bounced back in impressive fashion after a 1-2 start. He ranks third in the NFL in Total QBR (80.1) with 18 touchdown passes, three interceptions, a league-leading 73.5% completion percentage and 2,196 passing yards.

The Saints will have two games in six days over the next week. They are scheduled to host the Minnesota Vikings on Christmas Day.