Alec Ogletree and the Rams look to take control of the NFC West in Arizona

The initial feeling was not pain. More along the lines of “weird,” Rams linebacker Alec Ogletree recalled.

Ogletree had been making plays all over the field against the Arizona Cardinals at University of Phoenix Stadium last October when he planted his right foot and felt something give.

“I rolled over and couldn’t get up,” he said.

X-rays revealed a broken ankle, ending Ogletree’s season.

The injury caused a ripple effect throughout the Rams organization, one that a year later has made the defense faster and perhaps stronger.

Safety Mark Barron replaced Ogletree at the weakside spot after the injury and emerged as a hybrid force. That gave the Rams confidence that they could release veteran middle linebacker James Laurinaitis during the off-season to clear salary-cap space, and move Ogletree into that position.

“That play just kind of opened up the doors for a lot more stuff,” Ogletree said. “It wasn’t all bad.”

On Sunday, Ogletree returns to play the Cardinals as the leader of a defense that has helped the Rams to a 2-1 start and a spot atop the NFC West.

The Rams lost their season — and division — opener against San Francisco 49ers, 28-0. But the rebounded with a 9-3 victory over the Seattle Seahawks in a division game and last week defeated the Tampa Bay Buccaneers, 37-32.

Sunday’s game is the Rams’ last NFC West matchup until mid-December, when they conclude the season with three consecutive division games.

The Rams play a Thursday night game at Seattle on Dec. 15 and then finish with home games against the 49ers and Cardinals.

The Seahawks also finish the season with three consecutive division games.

A victory over the Cardinals on Sunday would give the Rams a 2-1 record in the NFC West before they play nine consecutive non-division opponents.

Coach Jeff Fisher is not belaboring the game’s importance.

“The division is not at stake right now,” he said.

Said quarterback Case Keenum, when asked what it would potentially mean to be 3-1 overall: “You can’t really think too much about what’s ahead. … There’s enough on our plate this week to think about the magnitude of things.”

Last season, the Rams defeated the Cardinals behind running back Todd Gurley’s breakout performance.

In his first NFL start, Gurley rushed for all but two of his 146 yards in the second half as the Rams held on for a 24-22 victory.

Gurley rushed for a season-best 88 yards and two touchdowns in last week’s victory at Tampa, but he has yet to break off the long runs that characterized his 1,106-yard rookie season.

So the Rams have relied on the Ogletree-led defense to secure victories.

Ogletree, 25, has made a team-best 29 tackles, including a game-saving hit-and-fumble recovery that secured the victory over the Seahawks.

He had eight tackles and broke up two passes against Tampa Bay in a victory that defensive end Robert Quinn preserved with a last-second tackle of quarterback Jameis Winston.

Last season, the 6-foot-2, 245-pound Ogletree made 10 tackles against the Cardinals before he was injured late in the third quarter.

Cardinals Coach Bruce Arians said this week that he has seen no drop-off in Ogletree’s play after the move to the middle.

“He’s a perfect [middle] linebacker for that system, because of his speed, and he can hang on the pass, and then still make up for it on the run,” Arians said during a conference call.

Ogletree and the defense will try to neutralize a Cardinals team that is 1-2 after last week’s 33-18 loss at Buffalo.

Carson Palmer, the 2002 Heisman Trophy winner from USC, had four passes intercepted in the final quarter.

“When you’re on the road and you’re playing in a tough environment and you’re playing from behind, it can go south real quick and it did on us,” Palmer said during a conference call. “I’m looking to bounce back this week … to redeem myself.”

The Rams rank 18th in the NFL in defense, giving up 366 yards per game. They are 17th against the pass (266 yards per game) and 17th against the run.

But Palmer holds it in higher regard.

“Personnel-wise,” he said, “it’s probably one of the best, one of the top two or three.”

Ogletree is in the middle of it.

He said he won’t be thinking on Sunday about the injury that helped put him there.

“I’m not going to go in there,” he said, “and worry about what happened last year.”

gary.klein@latimes.com

Follow Gary Klein on Twitter @LATimesklein