Kevin Blackwell was frustrated with Saturday's performance but offered credit to Crystal Palace following the narrow defeat at Selhurst Park.
A first-half goal from Alan Lee was the difference between the sides as United's battling display went unrewarded.
"It was disappointing but we knew it would be difficult with Paul Hart coming in, it added extra spice and the Palace lads worked their socks off for him. It is the worst time to play a team, when they've got a new manager in, they have something to prove," said United's chief.
"Palace have chased every ball and got decisions that mattered when it mattered. When you look at it, I suppose it is about time 'Harty' got a result against us at the fourth time of asking.
"In the first half I don't think we were as committed as they were and in the second, although we dominated, I don't think we created enough and they threw their bodies on the line so you have to give credit to Palace."
Blackwell added: "Last season we broke a club record for away wins and we've had a massive change in the squad - there's only Morgan and Montgomery left from the start of last season.
"We are good at home, not so good away at the moment, it is a balancing act - we are trying to get the best personnel out, both home and away. We've got half the job right, we've got to work on the other half.
"I was disappointed that we didn't start on the front foot, Palace got the goal and we had to chase the game. I felt we had the opportunity to get a result and although we dominated the second half we didn't work Speroni enough for all the possession we had. I'm not trying to kid anyone but we should have created more."
The United boss made just one change from the previous week's victory over Plymouth Argyle, recalling Stephen Quinn at the expense of Henri Camara.
He added: "We went with a 4-4-2 with Ward slightly deeper than Cresswell but Camara had a slight niggle so we didn't want to risk him. He wasn't effective when he came on, he didn't have the electric pace that he usually has.
"We haven't got a big squad, we can't lose players for any length of time. We'll have to use Henri when we can."
