Killie thought they were on the verge the William Hill Scottish Cup quarter-finals as they played out a thrilling Rugby Park replay with Aberdeen.
They led the Dons 3-2 with just a few minutes left of the additional half hour but were left stunned as Derek McInnes' team snatched victory at the death after Sam Cosgrove's penalty was followed up by an own goal from Connor Johnson.
It was a cruel defeat but Dyer knows his side cannot afford to let confidence levels sag as they prepare to take on Neil Lennon's merciless Ladbrokes Premiership leaders this weekend.
He said: "We've got another game – a tough game – on Sunday. Yes the boys are obviously down but we have to move on from the other night and move on quickly.
"There are a lot of lessons to be learned. It's a night that we have to put to bed but we will learn. I will learn from it too as manager.
"The boys are usually good at closing out games but it wasn't to be on Wednesday.
"We got caught up in the emotions a little bit and we have to learn from that lesson.
"But I believe we can go to Celtic Park and get a result.
"Whether it's a win or a draw, I believe there's enough in that changing room to get something this weekend.
"I have to believe that or it's not worth doing the job.
"Hard work will be key and we'll need the players to be on the money as we're facing a good side.
"But it's about us doing the right things at the right time and not feeling sorry for ourselves because we're not in the next round of the cup."