Dan Potts offered an honest assessment of his side's performance after captaining the Development Squad in their 1-0 defeat against Blackburn Rovers at Rush Green on Friday afternoon.
The young Hammers went down to a single goal which arrived just after the hour mark and proved too much for the home side to claw back.
The decisive strike by Potts' opposite number Darragh Lenihan stemmed from a Rovers' free-kick, and the defender felt his side hadn't done enough to warrant a different outcome.
He told West Ham TV: "I'm very disappointed," he explained. "We came into the game wanting to get the three points and the win.
"We felt that being at home and coming off the defeat at Bolton, we definitely felt that we would come here and give it our best shot to get the three points.
"Saying that, I don't think we played particularly well and I don't think we really deserved the three points. The next best thing would have been the 0-0 and to come away with a point, but we let ourselves down at a set-piece and that's the way the game ended."
The manner of the goal was particularly galling for Potts and the rest of the defence with the defining moment coming from a set-piece.
Potts had marshalled the defence well up to that point, but was left to rue how the winning goal came about.
"Playing at the back you pride yourself on clean sheets, so the disappointing thing from my point of view was that we conceded from a set-piece.
"They came here, had good shape about them and played on the counter attack. Obviously it's frustrating for us and we've got to have the know-how and the ability to break that down, which I believe we have got.
"Full credit to them. They came here with a game plan and their game plan worked better than ours. They're going home with the three points and we're going home thinking about what-ifs and what we could have done to get the three points ourselves."
Defeat dents the Hammers' hopes of finishing in the top half of the Barclays Under-21 Premier League table as they bid to secure a top-eleven finish for when the league splits into two divisions next season.
The U21s travel north to play Sunderland on Thursday in their final match of the league season, and Potts has targeted nothing less than a win against the Mackems.
"The emphasis is on Sunderland next week for sure. We'll regroup after this and then we'll be going up to Sunderland to come back with the three points like Blackburn have today.
"After this, the emphasis definitely has to be on trying to come away from Sunderland with something.
"The lads know their games, they know their strengths and I think you can see that when we all play to our individual strengths, that it's a good group and a good changing room.
"Off the ball as well when everyone works hard for each other its shows and nine times out of ten we come away with the result that we're looking for. Hopefully it will be one of those performances."