Nigel Worthington has praised Liam Boyce for having the courage to swap the Irish League for the Bundesliga at the age of 19.
Former Cliftonville striker Boyce has been rewarded by being called into Worthington's squad for the first time - they face Scotland in the Carling Nations Cup next week.
"Liam has scored a few goalsl. I have spoken to him and he is really enjoying himself. That is a big thing. He has moved to a different culture and taken on a foreign language. There are a lot of challanges for Liam and you have to give him credit," said Worthington.
Boyce, who moved to Germany last August on transfer deadline day, has already featured for Northern Ireland's Under-21 side and now Worthington believes he is ready to step up.
"It is an ideal opportunity to bring Liam in. We can have a real good look at him," Worthington told BBC Northern Ireland. "I have been fortunate to have worked him for the past three years in the Milk Cup and I knew about him at Cliftonville. I know his strengths and weaknesses.
"The move to full-time football has been good for him. He has trimmed down and become a lot leaner. Working on a daily basis has helped him physically and mentally.
Boyce will train alongside Northern Ireland's record scorer David Healy, who returns to the squad after being exluded for the friendly against Morocco in November.
Healy has sealed a move to his boyhood idols Rangers after a frustrating time at Sunderland and Worthington expects him to kick on.
"I gave David a little rest for the Morocco game, and I thought it would be good for him to get that hunger back at international level," he said.
"I am delighted he has got a move to Rangers and hopefully he can get some regular first-team football, get back on the goalscoring trail, which he is very good at and then bring that to Northern Ireland."