ST. LOUIS – Ryan Lindley didn't even know Drew Stanton was hurt at first, and then he had to focus on playing a game rather than worrying about his injured friend.

But as Stanton was about to be carted into the locker room, he reached out to Lindley and had a simple request for the newest Cardinals quarterback.

"Go win it," Stanton told him.

And so Lindley did, helped a ton by a defense that shut down the St. Louis Rams in a bloody, physical 12-6 win at the Edward Jones Dome Thursday night that gave the Cardinals their 11th win of the season – the most the franchise has had since moving to Arizona in 1988. It all but clinched a playoff berth for the Cardinals, assuming the Dallas-Philadelphia game does not end in a tie on Sunday night.

"A lot of this was for (Drew)," Lindley said.

But the game might have cost the Cardinals yet another quarterback for the season. Stanton's right knee injury is right near the same place as Stanton's season-ending injury back in 2007, but coach Bruce Arians said the extent of the problem isn't known yet. An MRI is coming Friday, and the Cards can only hope that Stanton won't join Carson Palmer as players lost against the Rams.

Lindley, with his experience surpassing rookie Logan Thomas on the depth chart, may end up as the third starting quarterback for the Cards this season. That makes sense in lost seasons like 2012, but not with a team atop the NFC standings.

Yet that's what has happened so far, and even with Stanton's injury, the smiles were not hard to find in the Cardinals' locker room.

"We keep saying next man up," said cornerback Jerraud Powers, whose pass knockdown on a fourth-down blitz ended what was essentially the Rams' last hope. "I was telling Pat (Peterson), 'We're running out of men. There won't be anybody to be up.'

"We believe in the system at the end of the day. No matter who is up, we believe."

The Cardinals didn't score a touchdown but neither did the Rams (6-8). The offense was about the right leg of rookie kicker Chandler Catanzaro, who rebounded from two misses Sunday to convert all four of his

field-goal attempts. It was the first time the Cardinals won a road game without a touchdown since 1935, according to the Elias Sports Bureau.

That's because of a defense that clearly had heard the praise heaped on a Rams' defense that had posted back-to-back shutouts. The Cardinals held running back Tre Mason to a mere 33 yards on 13 carries. The Rams began the second half with five straight three-and-outs as the Cards took control.

The Rams did get down to the Cardinals 1-yard line in the fourth quarter, trailing 12-3. But on third down, the Cardinals forced quarterback Shaun Hill into an incompletion, and Rams coach Jeff Fisher chose to kick the field goal with 6:07 left.

St. Louis didn't come close to scoring again.

"Everyone wanted to talk all that stuff about how great their defense is," Arians said. "I think they saw a good defense tonight. It was in red and white."

Arians called the play of his offensive line "outstanding" and for a second straight game, the Cardinals were able to move the ball on the ground. They rushed for a season-best 143 yards, with Kerwynn Williams gaining 75 on 15 carries and Stepfan Taylor adding 61 on 14 more.

Combined with how Stanton was playing (12-for-20, 109 yards), it looked like the Cards had finally found some decent offensive balance. But then Aaron Donald sacked Stanton – the Rams' lone sack of the game – and Stanton didn't get up.

"It's terrible when you lose someone, especially a key position like quarterback, but you can't let that be in your mind when you are trying to win the game," center Lyle Sendlein said.

When Lindley prepared to go in, Stanton was loaded on the stretcher and called Lindley over to deliver his "go win it" advice.

Lindley was worried for the guy who he developed a friendship with as backup quarterbacks all of 2013. But Lindley said "you have to snap back into backup quarterback mode" and his first play was a completion to Michael Floyd to set up a Catanzaro field goal.

Lindley only completed 4-of-10 passes for 30 yards, but "we got it done at the end of the day. That's the message."

Arians said he liked Lindley's poise and confidence, and that's not a surprise – Arians has proven often he will show his own confidence in whoever will be playing quarterback. Thomas was not and will not be an option if Stanton is out.

"It was not a time to put Logan out there," Arians said. "He will be a good player someday but he's not ready for this yet."

Lindley knows field goals aren't going to beat Seattle a week from Sunday, when the Seahawks visit in what will be the determining game in the NFC West race. Lindley didn't turn the ball over but he nearly did on an interception – and Williams almost lost a key fumble that tackle Jared Veldheer luckily fell on late in the game – but the Cards will have to have some passing production.

Losing quarterbacks "is not the best recipe for success," Arians said. "But we're going to continue to fight."

If the defense keeps playing like this however, Lindley and the offense won't have to do much.

"We just really, really, really wanted it bad tonight," defensive end Frostee Rucker said.

It's fitting that the Cardinals beat a red-hot team on the road on a short week, when a quarterback got hurt, because of their defense. It's the kind of adversity the team has somehow managed to muck through all season en route to the best record it has ever had in the desert.

Arians wore a lot of emotions after the game, calling it "one of the best wins I've been around." Given the circumstances and Arians' predilection to be emotional, it was easy to see why.

"I love it when nobody says you're going to have a chance to win," Arians said. "There's an 11-3 team and a team that is always 8-8. You figure it out."