NRL stars Jason Taumalolo and Valentine Holmes will reportedly be invited back to the United States for a second trial for NFL recruiters.

The pair impressed scouts from 14 NFL teams during a two-hour workout in Los Angeles on Saturday (Sunday AEDT), performing cone drills, a 40-yard (36m) sprint and other skills and agility exercises.

Five clubs have formally expressed interest in the players returning to again test their abilities in front of NFL scouts, according to News Corp Australia.

It is unknown when rampaging North Queensland forward Taumalolo and Cronulla backline ace Holmes will be requested to return to the US.

February's annual NFL scouting combine, a week-long showcase involving top college draft prospects, is one option for their return.

That, however, would clash with their NRL clubs' preparations for 2017 as pre-season training nears completion.

Taumalolo, 23, and Holmes, 21, say they remain committed to their NRL teams for 2017 -- the last years of their contracts -- but if offered an NFL contract would move to the US in 2018.

Valentine Holmes of Australia scores despite the efforts of Jermaine McGillvary. Mike Hewitt/Getty Images

"To come over here and have another go at a sport is another challenge for us," Taumalolo said.

The scouts - from the Eagles, San Francisco 49ers, Chicago Bears, Jacksonville Jaguars, Indianapolis Colts, Kansas City Chiefs, New York Jets, Buffalo Bills, LA Rams, Cleveland Browns, Arizona Cardinals, Green Bay Packers, San Diego Chargers and Seattle Seahawks - stood on the field with clipboards and stop watches as Taumalolo and Holmes performed drills.

A Philadelphia Eagles scout, who asked not to be named, said Saturday's workout was just the first step of their NFL journey. "They are big, strong athletes," the Eagles scout said on Saturday.

"The balance, strength, body control, the change in direction, they have that. "Their discipline today was outstanding."

The workout's organiser, Jeffrey Foster, president of the National Football Scouting, was impressed by not only their physical talent, but intellect.

"Both players were told what to do, they did it one time and they were done which I think speaks highly of them and their ability to listen, learn and to perform under what was probably a lot of pressure," Foster said.