Valentine Holmes has impressed in his NFL debut showing glimpses of the soft hands and speed that made him one of the NRL's most lethal weapons.

Holmes was anchored to the sideline for the first three quarters of the New York Jets' pre-season opener against the cross-town rival Giants on Thursday (Friday AEST), but made the most of his opportunities in the final period.

Holmes, taking to the field as a running back, made a gain of two yards (1.8 metres) on his first play and on his second carry was stopped for a loss of one yard.

Then on back-to-back plays he caught two passes from quarterback Luke Falk in the open field to show his speed and earn first downs. Holmes made a gain of 14 yards from his first catch before getting crunched by Giants' safety Kenny Ladler.