United were thumped 4-2 by their bitter rivals.
"I've just told them to dust themselves down and have an improved performance on Friday," explained Joyce to MUTV. "That's the good and bad thing about football - you're only as good as your next game anyway, even if we'd have won comfortably tonight.
"I've said before that this level is all about performances. The disappointing thing is there were some poor individual errors and, collectively, I'd like to see us do better as a team. We've had quite a settled side and not lost in pre-season but it bothers me more about the performance than losing.
"A lot of aspects were poor and not what we're looking for - both with and without the ball."
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