GLENDALE, Ariz. -- Although Arizona Cardinals quarterback Carson Palmer was listed as questionable with a sore right passing elbow, there was no question in his mind that he would play Sunday against the St. Louis Rams.
The Cardinals, trying to stay in the hunt for an NFC wild-card berth, needed Palmer, and he came through in a big way.
Palmer completed 27 of 32 passes for 265 yards and a touchdown, finding star receiver Larry Fitzgerald early and often, and the Cardinals cruised to a 30-10 victory over the Rams at University of Phoenix Stadium.
"I think the rest did him well," Cardinals coach Bruce Arians said of Palmer, who practiced on a limited basis last week but did not throw a single pass in workouts. "I think he set the second-highest completion percentage in club history. That was exactly the performance that we needed. He protected the ball extremely well and I can't say enough about the way he is right now and how the level he is playing at is extremely high."
It was the fifth win in the past six games for the Cardinals (8-5), and it keeps their playoff hopes alive, although they are still on the outside looking in.
If they do reach the postseason, they may have to do it without rookie safety Tyrann Mathieu, who suffered a left knee injury in the third quarter and had to be carted off the field.
Mathieu's status was not immediately known, but it did not look good and Arians said there are initial concerns that Mathieu may have suffered a torn ACL. He was tackled awkwardly after fielding a short punt, but seemed to be OK. Then he collapsed while jogging off the field.
"When a guy goes down and gets carted off the field, you've just got to keep your fingers crossed," Cardinals safety Rashad Johnson said. "You're hoping for the best and just wishing that whatever it is, it's a speedy recovery and we get him back on the field."
The Rams (5-8) have now dropped two straight since beating the Indianapolis Colts and Chicago Bears in blowout victories. They were held to 257 net yards against the Cardinals and 56 yards came on a reverse by rookie wide receiver Tavon Austin, who left the game in the third quarter with an ankle injury.
"I thought we'd do a better job than we did, but we couldn't run the football today and that's disappointing," Rams coach Jeff Fisher said. "Stats certainly are misleading with Tavon's reverse, but really that's the difference in the ballgame. They did an outstanding job against our run game. We turned the ball over, we had too many penalties and we got beat."
Fitzgerald looked like the perennial Pro Bowl receiver of old, catching a season-high 12 passes for 96 yards and a touchdown. The 12 receptions were one shy of his career high. It was his first double-digit reception game since 2010 and surpassed his previous season high of eight catches for 80 yards achieved in the season opener against St. Louis.
Palmer said he was worried about not having thrown a ball in practice but credited head athletic trainer Tom Reed and his staff.
"They are the best in the business," Palmer said. "We are fortunate to have them. He (Reed) had a plan from Monday on and we stuck to it. I had 100 percent faith and trust in him that he knew what he was doing and that he and his staff would have me ready to play."
As good as Palmer and Fitzgerald were, the Cardinals' defense shined just as bright on a brisk day with the retractable roof open under cloudy skies.
Inside linebacker Karlos Dansby stepped in front of a Kellen Clemens pass intended for tight end Jared Cook on the second play of the third quarter and returned it 23 yards for a touchdown.
It was the second interception for a score in three weeks for Dansby, who is back in Arizona after spending the previous three seasons with the Dolphins.
Another veteran free-agent addition, pass rusher John Abraham, came up with a stellar play of his own just six minutes later. With the Rams backed up deep in their own territory, Clemens dropped back to pass but Abraham tackled him in the end zone for a safety and a 23-3 lead.
Abraham added a third sack near the end of the game, giving him 11 on the season to surpass Lawrence Taylor and Leslie O'Neal for ninth on the NFL's all-time list with 133.
"I'm just glad we got the win," Abraham said. "Personally, I'm happy because it was one of my goals coming into this year, trying to get to 10 (sacks). Now I'm going to try and walk down (Michael) Strahan at No.5. He had 141 1/2."
Clemens finished the game 16 of 27 for 181 yards with no touchdowns and two interceptions.
Rookie running back Zac Stacy scored on a 1-yard touchdown run for the Rams at the start of the fourth quarter -- just the fifth rushing touchdown allowed by Arizona this season.
Cardinals rookie running back Andre Ellington added a 6-yard touchdown run late in the game following safety Rashad Johnson's interception to complete the scoring.
Palmer was 16 of 17 for 169 yards with one touchdown and no interceptions in the first half, helping the Cardinals take a 14-3 lead.
What the Cardinals said
"He told me he was going to play, so all you can do is take a man for his word. Carson's one of those guys who enjoys going out there and practicing and watching tape and doing everything that's necessary to prepare yourself, and that's why I knew it was pretty serious when he wasn't out there throwing the ball. But he did the handoffs and he did the run game and he was taking everything cerebrally and he was going to know where to go with the ball, and that was evident today." -- Wide receiver Larry Fitzgerald, on quarterback Carson Palmer, who starred Sunday despite being slowed during the week by a right elbow injury.
What the Rams said
"They had good coverage for what we had dialed up. I went to just throw it away and avoid the sack and got spun around a little bit. The ball came out not where I wanted it, obviously, and a good play by him. I wish I would have just either held on to it or found a way to dirt it in a different location." -- Quarterback Kellen Clemens, on his pass toward tight end Jared Cook that was intercepted and returned 23 years for a touchdown by Cardinals linebacker Karlos Dansby on the second play from scrimmage in the second half.
What we learned about the Cardinals
1. Arizona could be without rookie safety Tyrann Mathieu for the rest of the season after he suffered what looked to be a serious left knee injury. The Cardinals can replace him, given their depth in the secondary, but they will greatly miss his ball-hawking ability and even more than that, his accountability on the field.
"Even though he's a young guy, he prepares like a vet and he acts like a vet," outside linebacker John Abraham said of Mathieu.
2. Quarterback Carson Palmer is a tough son of a gun, and that can't be overlooked. Most observers were counting the days to see if he would last the season, given the state of the offensive line in front of him. However, he hasn't missed a snap this season, even after suffering a right elbow injury last week when he was hit and stripped of the ball by Philadelphia Eagles outside linebacker Trent Cole. Palmer didn't throw a ball all week in practice, but he was incredibly efficient and precise against the Rams. Incredible, because coach Bruce Arians said he didn't know until two hours before the game that Palmer was going to be able to play.
What we learned about the Rams
1. Officially knocked out of the playoff race Sunday by the Cardinals, the Rams now must simply try to improve during each of the final three weeks.
"We're going to get better," coach Jeff Fisher said, "and our focus is going on the Saints. That's what we're going to do. We're going to get better. We're going to take it one game at a time and we're going to get better."
2. The running game hasn't always been there for the Rams, and it if you take away Tavon Austin's 56-yard gain on an end-around, it wasn't there Sunday, either.
"That's a talented front seven we were going against," quarterback Kellen Clemens said of the Cardinals. "They've certainly played well all season against the run. We weren't able to lean on it in the second half because we got down. ... We'll stick with it. It's still the strength of our offense."