INDIANAPOLIS — Los Angeles Rams quarterback Matthew Stafford has been under center for two of the top receiving yard seasons in NFL history: in 2012 with Calvin Johnson (1,964) and 2021 with Cooper Kupp (1,947).

Through four games this season, Rams fifth-round pick Puka Nacua is outpacing both players.

Nacua’s 39 catches and 501 receiving yards so far are the most through a player’s first four games in NFL history, according to ESPN Stats & Information research. The rookie had nine catches for 163 yards and a touchdown in Sunday’s victory over the Indianapolis Colts. That touchdown — the game winner in overtime — was also the first of Nacua’s young career.

Through four games this season, Nacua has accounted for 32% of the Rams targets, which is second highest in the NFL. That volume is in large part because Kupp has been on injured reserve with a hamstring injury.

Kupp is now eligible to come off of injured reserve, and Rams coach Sean McVay said Friday that the Rams would start Kupp’s 21-day window to return and the receiver would practice this week.

When Nacua was asked whether he thinks he can sustain this pace and high workload, though, he said: “Shoot, if they keep asking me to do it.”

“I’m just trying to do my job,” Nacua said. “So whenever No. 9 throws the ball my way, I’m super happy because I know he’s making my job as easy as it could be.

“But trying to take care of my body. I’m grateful for the people in the training room and the staff we got here. Sleep is my No. 1 friend now. Going to bed as early as I can. 9, 9:30. 9:30, the latest.”

Nacua has been on the injury report each week since the season opener with an oblique injury, although he was a full participant in practice twice last week after his participation was estimated as “limited” Wednesday because the Rams held a walk-through.

Stafford was also playing through a hip injury Sunday in Indianapolis sustained during the game. Stafford described it as the muscles in his leg “shutting down” a little bit during the game, but he said he will play in Week 5 against the Philadelphia Eagles.

“Matthew put it in a spot for Puka to be able to make another big-time play,” McVay said. “I want to say he was nine catches on 10 targets. He was a man today, and he’s been a man throughout the first [four] weeks.”

Although Nacua’s performance has been one of the biggest surprises of the season around the NFL, Rams receiver Van Jefferson said he knew the rookie would be “really good” after seeing him during the offseason.

“He’s so detailed about everything,” Jefferson said. “You just knew coming into OTAs and training camp, how he’s going to be really good. He went in the fifth round? I’m like, ‘Shoot, he should have been a first-round pick.’

“He’s a great player, man. He’s a great kid. I’m so happy for him. He’s going to keep breaking records. His first touchdown is a game winner. How crazy is that?”