The Slovenian Under-21 international has joined Town from Wagner’s old club Borussia Dortmund for an undisclosed fee, becoming the club’s 10th capture of a hectic close season.
The 6ft 3in defender, 20, who has played for Slovenian U21s and was recently called up to their full squad, has signed a four-year contract until the summer of 2020, with the club having the option to extend the deal by a further year.
Stanković had been monitored by Wagner for some time and after being informed of his availability, Wagner quickly made his move.
The head coach said: “Having worked with Jon, I know he is an outstanding young talent and it is not normal that we’d get the opportunity to bring him here.
“When we did, it is great that we could move so quickly to complete the transfer.
“Jon will come in and work with the first team group, but he will be given time to develop further.
“He has the height of a centre back and his physical side will continue to develop; he is only 20 years old. He is already very comfortable in possession of the ball and knows our style of play very well; this will suit him.
“I am excited about having Jon as part of our squad, both this season and over the next few years.”
Stanković’s arrival follows the capture of central defenders Chris Schindler and Michael Hefele from German football, with all three players standing well over 6ft tall to add height to the club’s backline.
Stanković began his career at Slovenian side NK Domžale, where he made his debut at 16.
He was signed by Dortmund on an initial loan deal and spent his debut season playing for Wagner’s under-23 side, making 31 starts.
Last season he featured for Dortmund II in the Regionalliga West, making another 31 starts, with his performances leading to an appearance on the first-team bench in the Bundesliga towards the end of the campaign.