The 20-year old midfielder former New York Red Bull academy player has failed to figure for the Crew so far this term and he admits it has been testing him recently.
"I'm working hard in training and I'm not getting on the roster, which I honestly think is ridiculous," Duka told The Columbus Dispatch. "It's not working out and there's nothing I can do about it. I haven't been happy.
"It's tough to get motivated," he added. " ... I'm not going to say I'm a better player than (coach Robert Warzycha) has been choosing. I'm a different player. I definitely think I can contribute.
"Here I am, and I'm not even on the bench, I'm not on the team. It's like I'm on vacation."
Crew boss Warzycha said he felt let down by Duka's comments.
"All I have to say is that Dilly has the potential to be a good player in this league," Warzycha said. "If he's patient and works hard he can be a very good player, but comments like these don't get him anywhere."