GRUFF Rees revealed his frustration after the Ospreys were beaten by Connacht on Friday.
The reigning RaboDirect Pro12 champions failed to convert plenty of possession and territory into points as they suffered an unexpected 22-10 defeat in Galway.
"It was incredibly frustrating," said Rees, the region's backs coach. "It was one of those evenings when we could and maybe should have done better, but we can't have any complaints about the outcome.
"They were the better side."
The Ospreys played against the elements in the first half and looked to have given themselves a decent platform as they trailed 13-7.
But Connacht, well marshalled by veteran fly-half Dan Parks, stopped the Ospreys in their tracks as they failed to record a second win in successive weeks over the Irish Sea.
Rees added: "We were right in it, but to lose the second half 9-3 tells its own story.
"We lost a few set-pieces, gave away penalties at key moments, and that meant we couldn't really put together any sustained pressure despite plenty of good intent and endeavour.
"We were probably guilty of trying to play too much rugby for the conditions, but we had enough territory and possession to have got something out of it."
The Ospreys fell out of the top four — leapfrogged by the Scarlets — after the defeat.
And Rees wants an immediate response from his players when Edinburgh visit the Liberty Stadium on Friday.
"We've spoken about how tight it is in the top half of the table, that the top six this season are proving very consistent," he said.
"It's crucial that we pick up the pieces of this defeat, learn from it and show the right spirit.
"We've got two particularly tough games to come over the next couple of weeks, at home to Edinburgh and then away to Munster.
"Edinburgh is a crucial test of character for this group and we need the support of our fans. It's important that they do their bit to lift this team.
"It's probably fair to say that we are down to the bones in terms of depth now.
"We lost Ben John early on which meant that our options were limited when we were looking to rescue the game and we ended up with Kahn Fotuali'i on the wing.
"It was disappointing but this team has shown throughout the season that it's got plenty of spirit so we're expecting a good response next weekend. Hopefully the supporters will be there to help them."