The Australia global spent the 2016-17 season on loan at Huddersfield Town and played a key role as the Terriers clinched promotion from the Championship, scoring in the penalty shoot-out as they defeated Reading in the play-off final.
It has been an extraordinary turnaround for Huddersfield - a team that was in dire financial straits not that long ago and close to relegation last season.
"I said to them before that they were heroes for finishing fifth in the league".
"I think he is very happily ensconced in Berkshire, so it'll have to be a pretty big, tempting offer by my estimation to take him away from Reading".
But misses from the spot by Liam Moore and Jordan Obita gave Huddersfield the initiative and Christopher Schindler tucked in the winning spot kick to fire Town to the Premier League.
Yesterday is hard to take but never at the beginning of this season would we believe we have got to where we have and I'm sure we are all proud, as always, to be a Reading fan.
The Terriers will start next season in the top division of English football for the first time in nearly half a century, and Wagner, soaked with champagne, revelled in the magnitude of his side's achievement.
"We've had such a great season - what a wonderful pay-off to the season". "I didn't want to talk about it until the season was over". "So how we got here will remain for how we go forward".
"Whilst this typically includes some increased expenditure on playing talent in the short term, it is important that promoted clubs are committed to long-term financial responsibility. We're very happy that he was with us and maybe this is a further phone call that I have to do". "Even if we had won promotion to the Premier League, we would still need to do that".
The thrilling penalties followed a drab, goalless 120 minutes.
It is the first time in their history that they will be competing in the Premier League.
It hurts right now, but we will come back stronger.