Neil Lennon undertook the role of interim manager, following Brendan Rodgers’ exit from Park Head, midway through the season.
Now, the German manager, Wagner is the latest to be linked to the position
Wagner, 47, managed Borussia Dortmund’s reserves squad for more than four years, which proved out to be an underwhelming spell.
Later, the former Eintracht Frankfurt striker joined Huddersfield in 2015, when the club was playing in the Championship.
He proved to be a successful appointment, helping his side gain promotion to the Premier League.
Wagner parted ways with the club at the start of this year, after failing to produce results.
Neil Lennon-the favourite
The former Hibs manager remains the favourite, owing to his excellent run of form.
He has led the Hoops to six victories, without a single defeat in eight games.
Read more Celtic FC News, click here – Latest Celtic FC News
Moreover, the Old Firm win, followed by Sunday’s Scottish Cup semi-final win against Aberdeen enhanced his chances of becoming the next manager of the Bhoys on a permanent basis.