In an error-strewn trial played at rainsoaked McLean Park in Napier, Large, 18, and Walsh, 19, showed signs they will be knocking on the door for NRL action in the not too distant future.
The pair - both schoolboy rugby union converts - are viewed as Manly's long-term halves duo beyond Jamal Fogarty and Luke Brooks.
Large displayed a threatening running game on Saturday and was up for the physical battle, the five-eighth chopping down Queensland State of Origin star Kurt Capewell and jolting a ball loose from the grip of damaging Warriors ace Leka Halasima.
Halfback Walsh, meanwhile, brought a balanced kicking game which included a late field goal to rub salt into the wounds of a Warriors side boasting 10 NRL regulars.
The playmaker also had a hand in two of Manly's first-half tries as the Sea Eagles raced out to a 16-10 lead at halftime.
Manly coach Anthony Seibold would also be encouraged by how his young middle forwards stood up to a grizzled Warriors starting pack.
Manly have lost plenty of experience up front over the off-season but teenager Simione Laiafi and Paul Bryan held their own.
Laiafi clocked up 167m, while Bryan scored Manly's first try when he crashed in off a Brandon Wakeham short ball to cancel out Ali Leiataua's opener.
Walsh then came to the fore with a bomb that was batted back in field for Hugo Hart to go over before linking with Large down the right to set the wheels in motion for Clayton Faulalo's try.
Leiataua grabbed a second on the stroke of halftime before Walsh reasserted control with a grubberkick through for Hart, who touched down to record his double.
The game opened up in the final quarter of an hour with both coaches turning to their lesser-known names.
Warriors duo Harry Tauafiafi-Iutoi and Makaia Tafua traded tries with Manly's Blake Wilson and Zaidas Muagututia before Walsh added the final touch with a late field goal.