If star Saints cornerback Keenan Lewis couldn’t walk at all, he would’ve gladly accepted his team’s opinion that he should have sat out the rest of New Orleans’ 27-24 overtime defeat at home to San Francisco on Sunday after hurting a leg late in the first half.

Lewis, however, could walk. And he lives by the words, “If I can walk, I can go,” he remarked after the game. So he pleaded, contended and argued with members of the Saints’ training and coaching staffs to be let back in the game — and he didn’t stop until he got his way.

“It definitely doesn’t feel good,” said Lewis, as he displayed his visibly swollen left knee to reporters in the locker room multiple times Sunday. “(But) ... I’m an older guy on my team — they rely on me to be out there. So if I can walk, I’m going ... to go.”

Lewis’ valor didn’t prevent the Saints from falling to 4-5 and the 49ers from improving to 5-4. There was no way to know after the game whether his injury will keep him out of the Saints’ upcoming game at the Mercedes-Benz Superdome against Cincinnati (5-3-1). He wasn’t expecting to undergo an MRI until Monday.

Nonetheless, Lewis’ courage did prompt a sideline drama that was arguably just as compelling as the contest the Saints narrowly lost Sunday.

Lewis hurt himself defending a deep pass thrown from the Saints’ 46 to 49ers tight end Vernon Davis, whose route took him toward New Orleans’ goal-line. The pass was overthrown and incomplete, but Lewis fell to the ground in the end zone after lightly colliding with Davis.

Lewis was soon carted off out of view without much time left in the second quarter. The public announcer in the Superdome’s press box subsequently declared that the Saints’ leader in both passes defensed as well as interceptions over the past two seasons was out for the rest of the game, sending New Orleans’ fans into a social media panic.

But then, as the third quarter approached its midway point, Lewis emerged from a Superdome tunnel and began jogging, back-pedaling and changing directions behind the Saints’ bench. A trainer observed Lewis for a few moments before permitting the cornerback to walk up to and visit with head coach Sean Payton and defensive coordinator Rob Ryan.

After exchanging a few words with both his boss and his boss’ boss, Lewis pulled up his socks and re-entered the field for part of a defensive drive that resulted in the second of five punts the 49ers had to boot after halftime.

“He was lobbying to get back in,” the Saints’ Patrick Robinson said of his fellow cornerback, Lewis, whose status was comically upgraded to questionable after his return. “That’s the type of guy he is. ... He’s very passionate, and it showed.”

The episode was faintly reminiscent of the time Lewis verbally clashed with team officials on the sideline after the Saints yanked him out of the third quarter of a divisional playoff victory in Philadelphia in January with a possible concussion. The main difference was that Lewis won his case this time, and the Saints benefitted from letting him come back and log a handful of snaps as both an outside and nickel cornerback the rest of the way.

For instance, on a third-and-5 from San Francisco’s 28 late in the third quarter, Lewis swatted away a pass over the middle to receiver Anquan Boldin that would’ve gone for a first down had it been caught.

That was his second pass break-up on a throw to Boldin (15 grabs for 95 yards and a touchdown), but it came at a price. Lewis needed assistance from teammate Rafael Bush to stand back up, and then his pedaling on a sideline stationary bicycle he climbed after that 49ers series was slow and labored.

Regardless, Lewis was back in covering Michael Crabtree on a short pass from San Francisco’s 22 that the receiver dropped on a third-and-10 with fewer than two minutes to go and the Saints ahead 24-21. Lewis went to the sideline as his teammates tried to produce a fourth-and-10 stop that would’ve iced their fifth win of the season.

Instead, Crabtree reeled in a 51-yard reception that set up a game-tying field goal. The 49ers then recovered a fumble by Saints quarterback Drew Brees and made another field goal in the extra period to vanquish New Orleans.

It wasn’t the storybook conclusion Lewis’ effort deserved, and that pained the cornerback’s colleagues.

“The way he fought for us,” said Saints cornerback Corey White, “we just hoped we’d get the win for him.”

Lewis, though, wasn’t pitying himself.

“We’ve still got seven games (left this season),” Lewis said. “We’re still in the fight.”