Kyler Murray has played three games and had seven weeks of practice.

"There are obviously growing pains with this," the Cardinals quarterback said of his return from ACL surgery.

"I'm not discouraged at all with it."

Alone, that is positivity from a player the Cardinals need to be positive. But it also came in the aftermath of a disappointing 37-14 loss to the Los Angeles Rams at State Farm Stadium Sunday, a game that was ugly for both the offense and defense in a performance coach Jonathan Gannon lamented for a lack of energy.

Originally, Gannon had mentioned effort but corrected himself.

"I felt like our enthusiasm and our energy levels … probably wasn't effort. That's probably the wrong statement by me," Gannon said. "These guys come out and battle. It was the emotion and enthusiasm of the game, and we were a little deflated.

"That's on me."

Murray's issues weren't there when the game started, and the Cardinals (2-10) were actually ahead, 8-7, after each team had a possession. But after that? L.A. quarterback Matthew Stafford threw for 193 yards and three touchdowns in the first half alone, and the Rams (5-6) rushed for 228 total yards – the worst rushing performance by the Cardinals defense this season. The Rams had rushing plays of 56, 24 and 23 yards.

Rams running back Kyren Williams, who ran for 158 yards against the Cardinals in the meeting in L.A. but hurt his ankle late in the game and hadn't played since, returned to rush for 143 yards on only 15 carries, and added two receiving touchdowns on his six catches for 61 yards.

Nothing the Cardinals were doing matched those stats.

"We've got to take a good hard look at how we are setting up the week," Gannon said.

The Cardinals had changes defensively, without starting inside linebacker Kyzir White for the first time this season and starting three rookie cornerbacks for the first time as Marco Wilson was relegated to special teams work.

"I feel like the energy wasn't there," rookie cornerback Garrett Williams said. "I feel we played with high effort, but the energy was a little down than usual. It's one of those games. Chop it up, learn from it, and think about Pittsburgh (next week)."

The defensive issues mirrored those that cropped up in the first half against the Texans last week, although given the personnel and injury problems on that side of the ball, it wasn't a surprise. The Cardinals gave up the most total yards and points in a game this season.

"We have to continue to compete," safety Budda Baker said. "It's always about competing. I know our record isn't what we want it to be, but we have more opportunities to play football and that's what we have to do."

Murray's potential rebound game was still what was in the spotlight, and it looked wonderful after one drive. Murray was on point with chunk passes, and he executed perfectly a read-option for a touchdown at the end.

But in the eight possessions between that score and a TD pass to Greg Dortch with five minutes left, the Cardinals generated only 54 net yards on 32 plays.

"We moved it down seamlessly, executed well," Murray said. "Punched it in, and it kind of went downhill from there."

After the opening drive, running back James Conner had just two carries, the offensive line went through a rash of penalties at one point, and there was no rhythm to be had.

"It's hard when you are going three-and-out and the scoreboard is ticking on the other side," Gannon said. "That's deflating."

Murray was clearly trying to remain upbeat in his postgame comments, despite flinching at the box score.

"I know we'll be better because of it, but these are some of the things we need to go through," he said. "It's part of it."

Gannon said falling behind was going to make it difficult for everyone on the field, and when asked about any Murray regression emphasized "it's not just one guy."

The Cardinals have one game left before their late-in-the-season bye, a long trip to play the Steelers – a team battling for a division title. It'll be another game to show improvement, another game for Murray to face a fearsome pass rush and try and make progress.

That's what this season is about at this point.

"We just got our ass kicked," Murray said. "We played a good football game last week, we won the week before, but this, this was really the first time all year we got beat terribly."