"They are big, strong athletes," the Eagles scout said.
"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 Indianapolis-based National Football Scouting, was impressed by not only their physical talent, but intellect.
Foster organises the annual NFL combine that brings together the best college football prospects before each NFL Draft and said players usually train for six to eight weeks to perfect the cone drills, 40-yard sprint and other skills.
Rampaging North Queensland forward Taumalolo and Cronulla backline ace Holmes performed many of the drills for the first time and with just a few seconds of instruction.
Foster said elite, NFL-bound college players often mess up the three cone drill which assesses speed, agility and fluidity of movement and ask to do it a second time.
"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.
Taumalolo said the scouts indicated he would possibly suit the linebacker, tight end or fullback positions while Holmes was pencilled in as a wide receiver or safety.
Their lack of preparation may have hurt their times in the crucial 40-yard (36.6m) sprint - which acts as a barometer for NFL prospects.
Taumalolo ran his in about 4.9 seconds and Holmes was about 4.6 seconds, trailing top prospects in their positions at February's combine.
Taumalolo was also hurt by his height, with scouts told he was 6-foot-3 (191cm), but when he was measured at the workout he was just below 6-foot-1.
That may curtail his appeal as a linebacker and tight end where size is critical, while Holmes' sprint times will not set him apart from other wide- receivers and safeties.
What the scouts do like is they have played at rugby league's highest level.
"They are playing a world level so that gives them an advantage," the Eagles scout said.
"They have been under pressure and endured the demands and expectations of fans and all of that."
Foster said Jarryd Hayne's code switch with the 49ers last season piqued interest in NFL teams scouting the NRL's elite.
Taumalolo, 23, and Holmes, 21, said they remain committed to their NRL teams for 2017 - the last years of their contracts - and if offered an NFL contract would move to the US in 2018.
After each winning premierships and representing their nations and Taumalolo also winning the Dally M Medal this year, both are keen for new challenges.
"To come over here and have another go at a sport is another challenge for us," Taumalolo said.
The next step is for teams to contact their agents.
"It's a waiting game," Holmes said. "We'll have to see what happens."
- AAP
