For the veteran receiver, it was "all part of the plan."
Beckham suffered an injury to his left knee on a noncontact play with 3 minutes, 50 seconds remaining in the second quarter and was ruled out early in the third quarter. But he eventually returned to the sideline and watched his teammates pull out the late victory.
"This is everything I've ever dreamed of, you know," he told CBS Sports. "And there was a moment I was in the back room and they told me I was done, I couldn't play. And I had to come back out there and be a part of this because it's so much bigger than myself. And these boys pulled through and made it happen."
Beckham was running toward the right side of the field on a crossing route, but it appeared as though his left foot got caught in the turf. He dropped a pass thrown by quarterback Matthew Stafford and clutched his left leg as he fell to the turf.
Beckham took off his helmet while on the ground and was soon looked at by athletic trainers on the field before being helped off. He was looked at briefly in the medical tent on the Rams' sideline before heading to the locker room.
He was listed as questionable to return at halftime. With less than five minutes remaining in the third quarter, the Rams officially downgraded Beckham to out.
"We don't know yet, we're gonna wait to hear," he told CBS Sports when asked the extent of the injury.
The Rams' offense struggled after losing Beckham, who had two receptions for 52 yards and scored the first touchdown of the game when he beat Mike Hilton in the right corner of the end zone for a 17-yard score. But Stafford ultimately engineered the winning drive in the fourth quarter of Los Angeles' victory.
Rams veteran receiver Robert Woods, who has been out since November because of a torn ACL, said he comforted Beckham at halftime.
"Yeah I actually spent some time with him in the locker room before coming out after halftime and just, really just held him," Woods said. "It's tough. He's dealt with a lot I would say his whole career ... but just being able to hold him and say, 'I'm right with you.' I'll be here every step. Every rehab day. ... He's a competitor, I know he'll be back even stronger and hopefully he's back with us."
According to ESPN Stats & Information research, Stafford was 2-of-6 for 25 yards and an interception in the first half after the Beckham injury. He started 10-of-12 for 140 yards and two touchdowns, one to Beckham.
Beckham was signed by the Rams after being released by the Cleveland Browns at midseason. After a slow start to his Rams career, Beckham has delivered in the postseason. In three NFC playoff games, he had 19 catches on 23 targets for 236 yards and a touchdown, with a long of 31 yards. He was second only to Cooper Kupp in receptions and yards.
Beckham cashed in on another $1 million with the Rams' Super Bowl victory, maxing out the $3 million that was available in contract incentives tied to the team's postseason success. He had already made $2 million with their first three playoff wins and would have made $500,000 had the Rams lost Sunday.
Beckham tore his left ACL in 2020 while with the Browns. He's scheduled to become an unrestricted free agent next month.
ESPN Staff Writer Brady Henderson and The Associated Press contributed to this report.