TEMPE, Ariz. — The Arizona Cardinals have been a second-half team in two years under head coach Bruce Arians, outscoring opponents by an average of four points over 24 games.

A year ago, they were also a second-half team in terms of winning games, going 6-2 over the final eight games.

The Cardinals hope both factors hold true this season. They are confident they will, because they don’t think they have played particularly well on offense for an entire game this season.

For that reason, they are optimistic they can build upon a 7-1 record and win the NFC West for the first time since 2009.

“We keep hearing about this roll we’re on; I don’t think we’ve hit it yet,” quarterback Carson Palmer said. “It’s nice to win a bunch of games in a row, but we’d like to really pick up a bunch of steam on offense.”

That will be a key factor in the second half of the season, especially with a schedule that features five games against NFC West foes, starting Sunday with the St. Louis Rams.

The Rams are improving. And even if that weren’t that case, they usually give the Cardinals trouble.

They beat the Cardinals in the season opener a year ago, mostly because the Cardinals couldn’t protect Palmer. He was sacked four times, including three by right end Robert Quinn.

That performance led to the Cardinals trading away left tackle Levi Brown three weeks later.

The Cardinals upgraded that position with the signing of Jared Veldheer in free agency. He played well through the first half of the season and is the best left tackle the team has had since Lomas Brown in the late 1990s.

This season, the Cardinals have yielded 13 sacks and are ranked eighth in percentage of sacks per pass attempt (4.56 percent).

In 2013, they ranked eighth with a 7.14 percentage rate.

The play of Veldheer and right tackle Bobby Massie has a lot to do with that. Also noteworthy is that the Cardinals have given Veldheer and Massie little help. Backs don’t chip much and tight ends got out for passes.

That wasn’t the case last year when Palmer had few options if wide receivers were covered.

Arians hates using mass protection schemes and avoids them, if possible.

“You can only help so much,” Arians said. “You can plan on helping a guy, but as soon as they walk a linebacker up in the B-gap, your help is gone. You better block him.

“I learned a lesson a long time ago. We played Jevon Kearse and Kevin Carter. We had tight ends, backs chipping and we didn’t have a damn guy open. We got sacked like eight times. Next time we played the whole game empty (backfield) and beat them. He (the quarterback) still got hit, but we had guys to throw to.”

SERIES HISTORY: 71st regular-season meeting. The record is tied at 34-34-2. The Rams had won three consecutive games before the Cardinals beat them, 30-10, in Arizona in Week 14 a year ago. In the first game, Rams defensive end Robert Quinn had three sacks and drew a holding call. All came against tackle Levi Brown, who was traded three weeks later. Quinn has six sacks against the Cardinals in the last two years.

MEDICAL WATCH: RT Bobby Massie missed practice on Wednesday with a sprained right knee and ankle. He is expected to play on Sunday. If he can’t, Bradley Sowell will start. … LB Lorenzo Alexander (sprained knee) hasn’t practiced this week but is expected to play on Sunday. He is a backup and a key special teams player. … RB Stepfan Taylor likely will miss at least another game with a calf injury. Taylor did not play last week in Dallas. Marion Grice and Kerwynn Williams are the backups.

GAME PLAN: The Rams had eight sacks last week against the 49ers, so protecting Carson Palmer is a priority this week. If Palmer has time, the Cardinals have favorable matchups with their receivers against a young secondary. Rookie defensive tackle Aaron Donald likely will be matched up a lot against right guard Paul Fanaika, who has played reasonably well this season.

Defensively, the Cardinals will make stopping the run the priority. Rams quarterback Austin Davis has played well but he hasn’t seen a defense as diverse as the Cardinals’. They will give him a variety of different looks. The Cardinals only have eight sacks this season, and Austin is mobile. The Cardinals will blitz a lot and take their chances that their secondary can make plays against a young quarterback and receiving corps.

MATCHUPS TO WATCH:

Cardinals LT Jared Veldheer vs. Rams DE Robert Quinn – Quinn has six sacks against the Cardinals over the past two seasons. He had three in the opener last year, a big factor in the Cardinals’ decision to trade tackle Levi Brown three weeks later. Veldheer, signed in free agency, has played well through the first half of the season and hasn’t needed help in handling most left tackles.

WR Larry Fitzgerald vs. Rams secondary – Fitzgerald is no longer the focal point of the passing game, although he leads the team in receptions and yards. Fitzgerald can still do damage, even though he’s not running many deep routes down the sideline. He’s running well after the catch and has been effective on third downs.