An entertaining, hard-fought encounter was settled by Burak Yilmaz's second-half header for the Turks, and Fletcher saw plenty of positives in his side's evening.
"All the young players who played tonight did fantastic, and playing in an atmpsphere like this will only stand them in good stead for the future," the Scot told Sky Sports.
"In difficult conditions - the pitch wasn't great and it was an intimidating atmosphere - I thought we did extremely well, especially in the first half.
"As soon as they got the game they slowed the game right down with a lot of tactical fouls, got behind the ball and made it difficult. But we really should have got a goal in the first half and we had great opportunities when we broke on the counter-attack."
A predictably raucous atmosphere in the Turk Telekom Arena provided a distracting soundtrack to the evening, but Fletcher found greater difficulties in the unpredictable playing surface.
"Simple shouts like 'man on' and 'turn' were proving difficult to hear, but you've got to experience that, you've got to deal with that," said the midfielder.
"The biggest problem was the pitch, which wasn't good at all. It was difficult to play one-twos and quick passing because the ball was bobbling up, but I thought especially in the first half we did enough."