Injury-hit Albion had six development squad players on the pitch at the end of Saturday's 1-1 third-round draw with non-league Wrexham.
Unless the treatment room empties, boss Gus Poyet will have to stick with the youngsters in the replay with a home game against Newcastle the reward for the winners.
And 19-year-old full-back Sampayo, who made his debut against the Dragons, told the club's official website: "We play with each other week in, week out so we all know how each other play.
"If the gaffer plays the development squad in the replay it will be a real test for everyone. However, we know how each other play and I'm sure everyone will take their opportunity if it comes."