The surprise decision by National Rugby League superstar Jarryd Hayne to retire Tuesday and embark on a possible NFL career has sent shockwaves through rugby and has sparked curiosity about a rugby player taking on professional American football. But there is a great deal to consider about Hayne’s ambitious leap to the NFL and his prospect of earning a spot on a team’s 53-man roster.

There are obvious obstacles for Hayne to overcome like learning the often confusing rules, using a different ball, adjusting to NFL culture, but most importantly, understanding all of a team’s plays. Prior to entering the NFL, prospective players take a Wonderlic test, which is basically an IQ test for football players. They also endure rigorous fitness examinations in draft combines. Many potential roster players have come up short on the Wonderlic and didn’t impress during the combines despite showing clear signs of talent at the college level.

Such tests are thorough, which complicates matters for Hayne in the short term. The NFL begins Week 7 of a 17-week schedule on Thursday night, with many qualified practice-team players itching for the opportunity to be named to the active roster. The idea of a newcomer, without even high school football experience, let alone college or professional experience, suiting up at some point of the 2014 season seems like a major stretch.

However, Hayne has attributes that NFL coaches are interested in, making the transition perhaps less difficult. The 26-year-old has good size, with tremendous speed and quickness, and is good at tackling. In a best-case scenario, Hayne, who is listed at 6-foot-2 and 220 pounds, might be used as a running back, fullback, or safety. At worst, he might be utilized as an undersized linebacker, who can also play on special teams.

“It’s always been a dream of mine to play in the NFL, and at my age, this is my one and only chance at having a crack at playing there,” Hayne said in a statement. “I’m excited about the potential opportunities that lie ahead. I’ve known the deadline has been looming for me to make this call, and I believe the right time is now.”

Hayne had reportedly been mulling a move to the U.S. for months. He starred for the Parramatta Eels since 2006, and was nicknamed “Hayne Plane.” While he is gifted with great physical strength, he has also been criticized for caring too much about making spectacular plays that he sometimes withdraws during matches, showing disinterest during stretches.

Hayne's manager, Wayne Beavis, claims that he has been inundated with interest from NFL teams, though there has been no word about any possible tryouts. In September, Hayne visited the Seattle Seahawks, the Super Bowl champion team that already boasts an Australian player. Jesse Williams, a defensive tackle, was born in Brisbane and played rugby, but the difference between Williams and Hayne is that Williams spent two seasons with the Alabama Crimson Tide, a premier college football program.

Seahawks head coach Pete Carroll weighed in on Hayne, and described him as an “incredible athlete” and a “great competitor,” but acknowledged the difficulty Hayne will face in the short term to make an impact on the NFL.

"I think it would be really hard and a tremendous challenge," Carroll said at a press conference on Wednesday. "Only a certain few could do it. There would need to be a lot of patience from the [NFL team involved]. I don't think a guy could come in in the middle of a season. I think it would take more time than that. But we've seen guys over the years who have made the transition from other sports."

U.S. rugby head coach Mike Tolkin believes the transition is great for a rugby player to compete in the NFL. He echoed Carroll’s sentiments, claiming the NFL has too many complexities and intricacies for a rugby player to learn.

“I think it will be very difficult,” said Tolkin, in a phone interview. “I think [Hayne] is an unbelievable athlete, probably the top Rugby League player right now in Australia, but I think it will difficult for him to play in the NFL.”

However, Detroit Lions running back Reggie Bush, a nine-year NFL veteran who starred at USC under Carroll, sees the NFL potential in Hayne.

"I think he'd do pretty well actually," Bush said. "Because he's quick, he's elusive, he's powerful, he's fast, he has great vision and those are all the things you need to play running back in the NFL."

Hayne is regarded as the best player in Rugby League, and though there are distinct differences between rugby and American football, they both place a high importance on speed, toughness, and strength. Hayne could be a trail blazer for rugby players to pursue an NFL career. At the very least it could open up additional international scouting. There is almost certainly a great deal of talent outside the U.S., but probably not as talented as Hayne. It still poses the question: how much has the NFL done to develop foreign players?

“Not nearly enough, would be my answer,” said Mark Waller, NFL's executive vice president of international, in a phone interview. “I think that is probably the next phase of our development is to do more work on that. I think we have a lot more to do in that area.”

Carroll was quick to point out the potential of Australian rugby players.

"I've always thought it would be cool to recruit down [in Australia] and all that because there are some great players, and it's a great game,” said Carroll. “It's a very physical and demanding game, so those guys have all the same stuff we're looking for in our guys."

Hayne is not the first rugby player to draw interest from the NFL. In Feb. 2003, New Zealand's Jonah Lomu, perhaps the greatest rugby player ever, reportedly rejected a $10 million offer from the Denver Broncos.