West Ham beat Hull City on penalties yesterday, to ensure that they won the silverware.
The Hammers had won the first-leg 1-0, but a 1-0 defeat at the KC Stadium meant that the two sides had to be separated by spot kicks.
It came down to Martin Samuelsen to score the winning penalty, and the Norwegian held his nerve.
Etherington saw plenty to be encouraged by, and he has predicted that many of the development side can become first-team regulars in the future.
West Ham have high hopes for a number of their development squad, after they have enjoyed impressive seasons out on loan.
Samuelsen, Elliot Lee, Josh Cullen and Reece Burke have all been on loan in League One this term, and the quartet have all caught the eye.
West Ham also have the likes of Reece Oxford and Toni Martinez breaking through, meaning the future looks very bright for the London club.