Andrew Moran has been hailed as young player of huge potential.
He appears likely to get further chance to impress Graham Potter and the first team staff in the coming weeks and months.
Moran signed a three-year contract in a week which also saw him score against Crystal Palace under-21s at Selhurst Park.
The deal underlines Albion’s longer-term hopes for the 18-year-old attacking player from Knocklyon, in Dublin’s southern suburbs.
Head coach Potter told The Argus: “He is a young player we like a lot.
“He has been developing nicely in the 23s. I think he has got huge potential.
“The contract gives us that time and that mechanism to try and bring that potential out, because that’s what it is at the moment.
“I think he is still benefitting from the 21s.
“There will be some involvement with us over the season, I am pretty sure, because he has got quality.
“But he is in an area of the pitch where we have got a lot of good players as well.
“We have to just manage his pathway and manage his development.”
Potter’s comments suggested Moran would not be going out on loan this month.
He added: “If there is something we think is really, really good and it will help, then okay.
“But, at the moment, there are no real strong conversations in that way.
“I think we can be open-minded about that until the window closes.”
The 17-year-old arrives from Manchester City on a contract until June 2025.
The 21s play Liverpool at Lancing tomorrow (3pm).