Aberdeen manager Jimmy Thelin says Duk apologised to players and staff on his return to training and is “giving 100%” following his summer misdemeanours.
The Cape Verde forward was disciplined by the club after failing to return for pre-season as he looked to force a move.
However, Aberdeen announced last weekend that Duk had returned after “owning the situation” and “demonstrating his contrition”.
“When he came in, he apologised to the players, the staff and everybody around here and it feels genuine,” Thelin told Red TV.
“The players have taken care of him in a good way. The most important thing not only for him but for everyone is that everybody gives 100% for Aberdeen in training sessions and in games.
“It doesn’t matter who you are, it is for everyone. Just be clear with everyone and we will be fine.
“We have a really good team spirit. You can’t travel through time or change the past, but the most important thing is to look forward.
“For me, it is the starting point with him right now. The squad has accepted it and he has integrated really well with everybody. He is giving 100% in every training session since he arrived.
“So from there, he has to grow and adapt into the team, and get the connection with his team-mates. We know his qualities but from not playing football for a while he just has to train well, stay sharp and be ready for a game.”