THOUSAND OAKS, Calif. (AP) — A few hours after the Los Angeles Rams added a playmaking receiver, they lost a cornerstone of their NFL-best passing offense.

And they've only got two days to figure out how to overcome this upheaval before the next game in their Super Bowl chase.

Receiver Robert Woods is out for the season after tearing a ligament in his left knee during practice, coach Sean McVay confirmed Saturday.

"You're sick for Robert," McVay said. "He's epitomized everything that's been right about this place. Such a great competitor. Such a tough competitor. It's so unfortunate."

McVay said Woods' noncontact injury occurred when he "put his foot in the ground kind of weird" Friday. Woods felt well enough to finish practice, but a scan revealed a torn ACL — the first significant injury of Woods' nine-year NFL career.

Earlier Friday, Odell Beckham Jr. reported to the Rams' training complex and signed his contract after Los Angeles landed him as a free agent. Beckham practiced Saturday on his first full day with the Rams (7-2), and he could play Monday night at San Francisco.

Beckham only spoke obliquely about his midseason decision to leave the Cleveland Browns, not addressing the source of his discontent with that organization. With the Rams all in a somber mood after Woods' injury, Beckham focused instead on his task in Los Angeles, where he'll likely have an even bigger role than he might have anticipated.

"It's been a whirlwind of emotions," Beckham said. "Sometimes things don't work out in life, and when you take those leaps of faith, it's always scary in the moment. ... I took a lot of time in the decision-making, and it wasn't just to build anticipation or nothing. This is my life. I feel like I've been through a lot, and I'm at a point in my life where I'm ready to play football. I've dedicated and sacrificed a lot to be here, and it just happened that this felt right in my heart and my soul."

Beckham, who tore his ACL last season, and Woods were just getting to know each other when the new receiver arrived. Woods' injury cast a pall over Beckham's excitement.

"Everything felt right about coming here, except that moment," Beckham said. "This is a guy who called me on FaceTime. We shared words, and just how excited we were to work together and for me to be able to learn from him. I have no words for it. It was disheartening when I got the call. I know he was the heart and soul of this team. I'm just trying to do whatever I can to help. Those are big shoes to fill. My heart goes out to him."

Los Angeles leads the league in yards passing with new quarterback Matthew Stafford, and Woods is a vital component of that success alongside NFL receiving leader Cooper Kupp and fellow starter Van Jefferson. Contributing as a receiver, a blocker and an occasional jet-sweep runner, Woods is second on the roster with 45 catches for 556 yards and four touchdowns while also rushing eight times for 46 yards and another TD.

A team captain, Woods also has been a model of durability in his NFL career, never missing more than three games in a season due to injury.

McVay joined the Rams in the same offseason as Woods, Kupp and left tackle Andrew Whitworth. All three players have been foundational contributors to the offensive-minded coach's success.

"Rob Woods is one of the best dudes I've met," said Kupp, who tore the ACL in his left knee one day shy of exactly three years earlier, an injury that kept him out of the Super Bowl that season.

"He plays hard for the people he loves," Kupp added. "That's the way he lives his life. On game days, for three hours he's Bobby Trees. He's a whole 'nother animal. ... He's going to have a great template from me and other people who have been through it, and he's going to attack it to get back."

The Rams pursued and signed Beckham earlier this week because they were already thin at receiver behind their three starters. DeSean Jackson demanded to leave Los Angeles last month with disappointment in his lack of playing time, whilel rookies Tutu Atwell and Jacob Harris are out for the season with knee injuries.

With Woods also unavailable to an offense that has run three-receiver sets almost exclusively, the Rams' depth chart at receiver now consists of Kupp, Jefferson and Beckham — followed by rookie Ben Skowronek, who has taken nearly all of his 37 offensive snaps in garbage time this season, or J.J. Koski, who was promoted from the practice squad last week.

That means the Rams will face the 49ers with a third receiver on the field who has little or no game experience with Stafford and this offense.

If the prospect worries McVay, he isn't saying so.

"You always have to be able to pivot," McVay said. "You've got to have agility and flexibility based on uncertain scenarios. This is certainly one that you didn't expect, and it happens a little bit later in the week of preparation. Makes it a challenge, but whatever I say is going to be an excuse."

Woods played four seasons in Buffalo before the Southern California product returned to his hometown with the Rams in 2017. Early last season, Woods agreed to a four-year, $65 million contract extension that begins in 2022.

In 4 1/2 seasons with the Rams, Woods has 367 catches for 4,626 yards and 23 touchdowns while also rushing for 485 yards and five scores.