SAN FRANCISCO 49ers will teach Lawrence Okoye American football "from scratch" after signing the Olympic discus thrower who has never played the game.

Last year Okoye was 12th at London 2012, but switched to his new sport without a competitive game to his name and, in doing so, rejected overtures from athletics, rugby union and the option of beginning a legal career.

He was not selected on the final day of the NFL draft but signed with this year's Super Bowl finalists as a free agent.

"I am not in a position to be looking too far into the future," he said. He rejected an offer to study law at Oxford University to commit to a "baptism of fire" on America's west coast. "Oxford is never going to leave my mind and I do plan on going there.

"I'm absolutely delighted how things have worked out," Okoye said via a teleconference from Georgia. "The 49ers are the best fit for what I am trying to do. This could be a great success story."

Initially, he had intended to carry on with the discus after London and aim for Rio 2016. But he subsequently decided to switch to American football and impressed scouts at the Super Regional Combine.

The persistence of the 49ers and their defensive line coach Jim Tomsula proving decisive. Okoye has only once put on a helmet and full pads but has made an unspecified "long-term commitment" to the franchise.

Coach Jim Harbaugh told the San Francisco Gate: "He's just an Adonis. Just a great physical specimen of a man. I can think of some other adjectives. Our creator created a beautiful man."

"It's the team I felt wanted to do the most work with me," added the 21-year-old Okoye, who is expected to play as a defensive lineman.

"Jim Tomsula has a great background in NFL Europe, developing players without much background in the game.

"It's going to be a baptism of fire but that's part of the process. It's going to be a ridiculously tough, tough process.

"I will have to work even harder than everyone else, I have a lot to catch up on. I know as much as I can without having played but I am still an outsider looking in.

"They have made it clear they are going to teach me everything from scratch."

Okoye joins Manchester-born Menelik Watson on the west coast of America after Watson was selected in the second round of the draft by the Oakland Raiders while Crawley-born linebacker Tom Wort joined the Tennessee Titans as an undrafted free agent.