Nick Haycock laid down the law to some members of his Development Squad after a below par performance led to a 1-0 friendly defeat against Luton Town at Rush Green.
The coach was unhappy with his team which featured ten changes from their last Barclays Under-21 Premier League match.
The game provided an opportunity for players who have not seen much game time recently to catch Haycock's eye but he was left unimpressed by their efforts.
He told West Ham TV: "I'm very disappointed. We were as poor as I can remember for a long time in the first half and everything that we talked about before the game we didn't do.
"I asked a question of a group of players who had one player that started our last league match in Danny Whitehead, but apart from that the team was totally changed and players were playing together for the first time.
"For me football's a common language, they've all been training with us, they know the standards we expect of them, they know the way we play and they didn't produce a performance."
The only goal of the game came in a first half in which the away side were dominant for long spells and deservedly went ahead when their captain Matt Robinson saw his left foot piledriver find the bottom corner.
Despite a much improved second half showing, the Hammers failed to take any of the chances they created and slipped to a defeat against an opponent who attracted high praise from Haycock.
"If these players are going to be Premier League players they might have to experience playing in the Conference or League Two and when we played Southend in pre-season they give you a different test.
"Most of the teams we play against in this league play patient build-up play in front of you and in some of the games we find it easy because they can't get in our box.
"Today Luton played in behind us and you could see our lads weren't used to dealing with it.
"It was a great experience for them and I can't thank Luton enough for coming, there's no snobbery at this football club, the game will always be about hard work and intelligence and I think Luton showed that the most in the first half today."
The defeat was just the squad's second in ten matches since the beginning of the season but it clearly rankled with the team's coach.
Being top of the Barclays Under-21 Premier League hasn not been achieved without the hard work and application which Haycock demands of his team and he believes one or two players are in for a wakeup call.
"Tomorrow morning they'll think they're coming in for a cool down but they'll have a shock because I don't think their work rate demanded that they get one tomorrow and they have to learn that hard working mentality.
"I've already told them to be in at half past eight for nine which is an hour earlier than usual and they'll be in for a shock in the morning and rightly so.
"Yes we were better in the second half but I need to let them know while we're doing well we're not taking our foot off the gas.
"Win, lose or draw we will always set high standards."