The Scottish champions fielded a youthful line up in their pre-season clash with St Pauli on Saturday, going down to a 1-0 defeat in Germany thanks to a goal from Christopher Nothe.
With the bulk of their first-team squad rested ahead of the European third qualifying round first-leg clash against Polish side Legia on Wednesday, Celtic boss Deila insisted the friendly was an important learning curve.
However, the Norwegian knows that his side will need to be far more clinical if they are to challenge both at home and abroad this season.
"First of all we want to have the ball more and create more," he told Celtic TV.
"We could have got a result but I think the performance was good and we need more games like this for our young players.
"Ambition is high but it was a very good experience for the young boys to play internationally and at this level."
