"Commitment-wise we couldn't have asked for much more and it is always difficult when you have lost a player," he insists.
"The attitude was good but maybe we were let down with the quality of the final pass.
"We have to show the same attitude, which we had questioned in the last few away games, between now and the end of the season - but it is obviously a disappointing result.
"There is no doubt that in both halves of the game Crystal Palace wanted the game to finish.
"In the first half we had two great chances at the end after we had lost Connolly, and then late in the game when we were going gung-ho, trying to get something.
"They have to show that same commitment when they have got everybody on the pitch and that is what you expect of them week in, week out.
"We know they have the quality as footballers and if they can add both to the game there is a possibility they can achieve anything.
"But there is no success without hard work and there is a lot to be done here."
Looking back on the stalemate against Derby, he adds:
"On Saturday we had early chances in the game but if you don't take your early ones, especially in this league, you can be punished.
"We were a bit lucky as well when they had one right at the death and it was disallowed.
"But we should have been out of sight by then, especially in the first 25 minutes."
Peter remains upbeat about making the play-offs and concludes:
"There will be no stone unturned to turn it around.
"There are 12 points to play for but we need to play as well as we can between now and the end of the season."