Colchester United manager Geraint Williams accepted that he had endured a terrible return to one of his former clubs as the U's were beaten 5-1 at Derby County.
Williams' side were 3-0 down within the opening half-hour and never recovered at Pride Park.
He said after the reverse: "We came here thinking we could set a game plan out and frustrate Derby early on and hopefully go on and win it, so to concede early was a big disappointment.
"I think it's fair to say we didn't handle Giles Barnes very well in the first half and, although Derby didn't create an avalanche of chances, they were very clinical in their finishing.
"We changed the system at half-time to match them and, for the first 15 minutes, we got a goal and another chance or two, but then the penalty killed us.
"This has been a big setback but we will regroup. This has been the low point of the season, but there are more highs to come."