Olympic discus finalist Lawrence Okoye has never played football, but after signing with the San Francisco 49ers, he said he thinks that through hard work he can make an impact in the NFL.

The 49ers signed Okoye, 21, as an undrafted free agent and plan to train him to become a defensive lineman. The 6-foot-6, 304-pound British athlete wowed scouts at the super regional combine at Cowboys Stadium in April, running the 40-yard dash in 4.78 seconds and posting impressive results in the vertical jump (35 inches) and broad jump (10-foot-5).

Lawrence Okoye will try to make the transition from discus thrower to professional football player. AP Photo/Tony Gutierrez

He holds the British record in discus (68.24 meters) and qualified for the finals in the event at the 2012 London Olympic Games but finished last.

He told the San Jose Mercury News this week that he was "terrible" when he first began throwing the discus at age 18, but his success there gives him confidence that he can work hard enough to have success in professional football. Okoye also played rugby as a teenager.

"I had to work really hard to become good at it. It's going to be the same path in this sport," he told the newspaper. "When I start out, I'm not going to be as good as everybody else. I'm going to look out of place, that's for sure. But with some work and with time and effort, I know I can catch up and hopefully become a dominant player in the league."

He made pre-draft visits to the Chicago Bears, New Orleans Saints and 49ers. San Francisco coach Jim Harbaugh said he felt "inadequate" standing next to him.

"An Adonis, a great physical specimen of a man. ... Our creator created a beautiful man," Harbaugh said of Okoye on Saturday, according to the Sacramento Bee.

Okoye said that he put on a helmet and pads for the first time when he visited the Saints.