With just over five minutes to go in last Thursday's game against the 49ers, Rams wide receiver Pharoh Cooper was standing about three yards into the visitors' end zone at Levi's Stadium, ready to receive a kickoff.

San Francisco had just cut Los Angeles' lead to eight points at 41-33. One more scoring drive — or at least a drive that ate up clock — could send the Rams home happy.

Of course, that's not quite how it all unfolded. Cooper fielded the kick and based on the called return, began running out of the end zone. The second-year pro darted his left, getting to the number at the 10-yard line. He continued running upfield until he braced for impact at about the 25-yard line. And that was when Niners wide receiver Victor Bolden forced a critical fumble. San Francisco's Aldrick Robinson made an outstanding play to dive and recover the loose ball, and the damage was done: 49ers ball on the Los Angeles 29.

"Broke through to the second level … cut back, and boom," Cooper recalled on Monday. "He came faster than I thought — came in and knocked the ball, you know? It was just one of those plays where he just went in there, closed his eyes I feel like, and hit the helmet on the ball. I was running — he didn't touch me, I didn't touch him, his helmet just hit the ball.

"And I mean, really, just a good play on his part," Cooper continued. "But that's not acceptable. That can't happen again, especially at that time of the game — in the fourth quarter. I take complete blame for that, because I should have better ball protection. But it was just one of those plays where he just made a good play."

Fortunately the story has a happy ending, as L.A. held on to beat its Bay Area division rival 41-39. But Cooper had some nervous moments on the sideline as he watched the 49ers nearly tie the game.

"When they scored, I was kind of like, 'Man, that's my fault.' You know? I gave them the ball back. So when they went for two and missed the two-point conversion, I kind of had a sigh of relief," Cooper said. "Once they missed the two-point conversion, I actually came off the sideline and gave everybody on defense a high five saying, 'Good job. Good job, that's my fault.'"

The Rams' special teams unit has made an uncharacteristic amount of mistakes over the first few games of 2017 — Cooper's fumble, a pair of muffed punts, and some costly penalties. Through it all, Cooper said special teams coordinator John Fassel — more commonly referred to as 'Bones' around the Rams facility — has been a steadying force.

"Really, he's just saying take coaching. Don't let it happen again. Learn from it," Cooper said. "That's kind of the main thing he's said — learn from it. Better it happens now, earlier in the season, than later."

Cooper added that Fassel has expressed full confidence in him as a kick returner.

"Nothing's going to change. I'm still going to run the kick returns as hard as I can, taking it out when I need to," Cooper said. "But as far as the whole special teams unit, just learn from our mistakes, don't let it happen again. There were some silly mistakes and we've got to be better than that — in that type of a game, too, a close game like that."

Aside from the fumble, Cooper has done a nice job since taking over as the Rams' primary kick returner for the last three games of last season. The South Carolina product returned 14 kicks as a rookie, including a 51-yard return against San Francisco on Christmas Eve. He's currently No. 2 in kick return yards and No. 7 in return average through the first three weeks of 2017.

"I feel very comfortable back there," Cooper said.

The wideout had not returned kicks since his freshman year as a Gamecock, when he finished with a 22.4 yard average on 16 kicks. And since entering the league, Cooper has learned being successful in that area is more complex than some may think — starting with the decision to take the ball out of the end zone or take a knee for a touchback.

"It just depends on the return — which return is called," Cooper said. "There's certain things that go into it. The height of the ball, the trajectory, how long it stays in the air, if I need to take it out depending on how deep I am, if it's a line-drive kick — it just depends. There's a lot that goes into it — a lot more than people know. And especially with the front line and the wedges, it's a real-life long play — you've got to strain for a good amount of time to bust one of these."

But Cooper feels with the strong partnership he's built with the blockers on the unit, that's exactly what the Rams will do this year.

"We can always talk to each other about what we see on the sideline when we get the film," Cooper said. "So we have a great connection. I feel like it's going to help us out in the long run. We plan to bust a couple this year."