In a scrappy first half which only saw a handful of points before a sin bin to Tigers' forward Stefano Utoikamanu, the visitors' problems on the scoreboard were made worse by the two players being ruled out.
Maumalo was the first to be taken from the field in the opening minutes of the contest in just the second minute of the game after attempting to make a tackle on Sea Eagles' youngster Tolutau Koula.
Racing out of the line to shut down a pass which had gone to ground out the back, Koula found himself under the tackle with the knee of teammate Oliver Gildart appearing to make contact with the winger's face.
He lay motionless on the field before play was stopped, with Maumalo being taken from the field and eventually failing to pass his head injury assessment test.
It caused an immediate reshuffle for the Tigers, with Tyrone Peachey slotting into the centres and Oliver Gildart moving onto the wing to take the vacant spot of Maumalo, who will also have concerns for a nose injury after suffering a bleed on the way off the ground.
Later in the half it was interchange prop Thomas Mikaele who found himself in an awkward position, copping a knee and boot to the face.
He appeared to stagger to the ground, with the referee calling time off before the bunker's independent doctor ruled him out of the remainder of the game with Category 1 symptoms.
The Sea Eagles went on to win the game 36 points to 22.