Jared Goff isn’t feeling well, and Rams’ offense has been sickly

The Rams offense, stricken by a chronic case of lethargy and ineffectiveness throughout the season, suffered another mild setback Wednesday:

Quarterback Jared Goff was absent from practice, missing on-field preparation for Sunday’s game against the Atlanta Falcons at the Coliseum.

Coach Jeff Fisher said afterward that the No. 1 pick in the draft had attended team meetings but was kept off the field because of illness.

Case Keenum took first-team snaps in Goff’s place.

Goff was at the Rams’ facility in Thousand Oaks in the morning, Fisher said. He received treatment, participated in meetings for the installation of the game plan and observed the walk-through before practice.

“Just was not feeling well,” Fisher said. “So we felt it was best to send him home.”

Most NFL teams give players a scheduled day off on Tuesdays. Rams players are off Thursdays, so Wednesday’s workout is typically the longest and hardest of the week.

Goff is preparing for his fourth NFL start. Fisher said “he understands what we’re doing” and that his absence does not set him back.

“Not at all,” Fisher said. “Not concerned about it.”

The Rams’ offense, of course, has plenty of other concerns.

It ranks last in the NFL, generating only 284 yards per game, and also is last in scoring at 15 points a game. The Rams are 30th in rushing, 29th in passing.

“It’s easy to point a finger, and none of us are about that,” offensive coordinator Rob Boras said. “We all need to coach better. We all need to play better, and prepare better.”

It has been one year since Boras took command of the Rams’ offense.

With four games left in the 2015 season, Fisher fired Frank Cignetti and promoted Boras from tight ends coach to interim offensive coordinator.

The Rams won three of their last four games — they still finished last in the NFL in offense and passing — and Boras parlayed his stint into a full-time job.

A year later, with four games remaining, the Rams’ offense is basically in the same spot — but with a running game that has digressed from 2015.

Running back Todd Gurley rushed for 1,106 yards and 10 touchdowns last season en route to being named the NFL’s offensive rookie of the year. This season, behind the same line, he has run for 679 yards and four touchdowns.

Last week against the New England Patriots, the Rams ran only 18 first-half plays, including a kneel-down by Goff in the final seconds.

Before Goff’s 66-yard pass to Kenny Britt late in the fourth quarter, the Rams had produced only 96 net yards.

So how will the Rams keep pace with the Falcons, the NFL’s third-ranked offense that averages a league-best 32.2 points a game?

“We tried to take some shots in the last couple of games,” Boras said. “We understand we have to score some points, and that all sometimes leads to long incompletions, and second-and-longs, and third-and-longs.”

Asked if the team considered a change in philosophy or game planning, Boras said “we’re always trying to evaluate” and referenced constant attempts at subtle changes.

“The definition of insanity is doing the same thing repeatedly and expecting different results,” he said, adding, “They’re little things that the players would know that we’re trying to do things different. Not carrying over to Sunday, but we are trying to change things.”

With the Rams sitting at 4-8, this week’s news of a two-year contract extension for Fisher has riled fans, many of whom do not want him back regardless of whether the Rams win out.

Even if Fisher returns, it appears obvious that there will be changes in the offensive coaching staff.

Boras oversees a unit that includes quarterbacks coach Chris Weinke, offensive line coach Paul Boudreau, running backs coach Skip Peete, receivers coach Mike Groh, tight ends coach John Lilly and several assistants.

How the Rams perform against the Falcons, Seattle Seahawks, San Francisco 49ers and Arizona Cardinals could determine the future of Fisher and his staff.

Much of that evaluation is riding on Goff’s performance.

And perhaps finally finding a remedy for an ailing offense.

gary.klein@latimes.com

Twitter: @LATimesklein