City lost 2-1, with Divine Mukasa scoring for the visitors, though he also missed a penalty early on.
Wilkinson told City's website: “It’s a real big lesson for us in terms of the level we need to be at both in this competition and in senior football.” Wilkinson pointed out.
“And how you have to be so clear, accurate and precise in all details of the game.
“I just felt for 15 or 20 minutes in the first half we weren’t that and we’ve lost the game because of it.
“They had three shots on goal and two on target and we had something like 16.
“The nature of the goals were really disappointing and at this level you will get punished.
“We created more than enough moments to win the game and were much better in the second half but that 15/20 minutes cost us.”