Town contacted the Reds to ask permission to speak with Winkler yesterday and after that was granted, they held discussions with the former Rot-Weiss Essen director of football – and he has now joined the club.
Winkler worked with Siewert during the Town head coach’s time in charge at Essen from 2015-16 – and the pair have kept in close contact.
The duo did their coaching qualifications together in Germany. Winkler will join up with Town’s squad, who are flying out to Portugal for some warm weather training ahead of Tuesday’s home game with Everton.
“Andy and Jan worked together at Essen and he told me about this offer and I said: ‘ok’,” said a disappointed Reds head coach, Daniel Stendel. “I said I wanted him to stay, but from the outside, this is a big chance for him to work in the Premier League.
“I am disappointed he left and I think we worked very well in the first seven months together. But it is the way in football. Players leave and this time, Andreas has left the club.”
Barnsley chief executive officer Gauthier Ganaye added: “Obviously, when a Premier League team comes in for you it is attractive and we couldn’t deny Andreas this opportunity in his career, with him also having a buy-out clause in his contract. We have had a couple of days to work on a replacement and it will be up to Daniel to decide who he wants to take the role now.”