Carlos Hyde has seen his roommate reading the Bible most days they've been together, but not even divine intervention could have saved Jarryd Hayne from what he was about to confront in the NFL.

At least that's what Hyde, who seems more interested in the Mad Monday tradition than the NRL, first thought of the undrafted rookie attempting to become an American footballer.

"I was like 'man, when you get these pads on, you might get killed'," Hyde remembers thinking about the former Parramatta superstar. "But he's shocked everybody, running hard, playing fast, even with his pads high he's still playing hard. He's a guy who came in here and wants to make this team.

"He's doing everything he has to do to make this team. It's knowing your place, going on the field, doing your assignment right, playing fast. Like coach always says, do the little things and make the little things count, and Jarryd is doing that."

Hayne's first roommate, Lance Lewis, was cut from the 49ers roster in April and he has since been partnered with the man who took him under his wing from his early days in camp four months ago.

Hyde, expected to start the season at running back for the 49ers in their first game against the Minnesota Vikings at Levi's Stadium on September 14, has heard all about how big of a deal the Hayne Plane is back home as well as "this thing called Mad Monday".

"We talk a little bit about the league back in Australia. He was telling me about this thing called Mad Monday," Hyde said.

"That sounds pretty exciting. It's something I would like to join one day. He tells me some stories from back in Australia. It's some pretty crazy stories. But it's good over here.

"I've never been out of the country, so it's good to hear a different perspective from someone outside the country. Them telling me about what goes on out there. I ask Jarryd all the time, 'so you're pretty famous ah? You get a lot of love back there?' He's like 'yeah, I do'. I think that's pretty cool."

While there's plenty of intrigue in Hayne the NFL player at the moment, there's not much to Hayne the roommate.

"When I come in the room, Jarryd is either reading the Bible or talking to his family on FaceTime, that's it," Hyde said.

Despite the spotlight shining brightly on the man fast developing a cult following, he hasn't lost the respect of his teammates as a result of the attention.

"We're in the same room every day. He's like a brother," Hyde said.

"Everybody in there is like a brother. When I found out he was my roommate, 'it's my guy Jarryd'. I didn't think much of it, I always thought Jarryd was a cool guy. I wasn't really thinking much of it.

"Everybody likes Jarryd, given the attention - we already know Jarryd comes from Australia where he has a big name there. Jarryd's a big-name guy. We're not going to give him any hassle about it. Cool guy man."

As for advice?

"All I really tell Jarryd is play fast, get comfortable with the game and also get your pads low," Hyde said.

"You don't want to be running high in this league with guys coming at you wanting to kill you because you have the ball. You've got to protect yourself.

"He [is] always in film, always in the playbook, always asking questions, which is good. He's really improved and it's good to see."