When Celtic take to the field at Lyon’s Groupama Stadium on Saturday night, the vast majority of the attention will be centred on one man.
Moussa Dembele had an impact on the Hoops faithful that few others have managed since Henrik Larsson.
His goals against Rangers and Manchester City stand out, but his real legacy was being the star of the ‘Invincibles’ – undoubtedly the best Hoops team since Martin O’Neill’s men.
Dembele’s re-acquaintance with Celtic will be a brilliant moment, in an otherwise meaningless friendly competition.
However, he won’t be the only ex-Celtic star going up against his former employers.
In a less glorious and box-office period for the club there was Jason Denayer.
The centre-back, who joined on loan aged 19 in 2014, was a big hit with the Celtic faithful throughout his one and only season in Scotland.
He helped the team to a double under Ronny Deila in a campaign that should really have been rounded off with a Scottish Cup triumph.
Denayer scored five goals in 29 league appearances – with a further strike arriving in the Scottish Cup.
He was about as accomplished a 19-year-old as we’ve seen at Parkhead – perhaps only bettered by Dembele at that age.
Belgian international Denayer was a victim of playing alongside Virgil Van Dijk.
The defenders forged a great partnership both on and off the pitch, but Van Dijk’s presence often means Denayer in devalued in retrospect.
But the defender, now 25, is unlikely to care too much. Since leaving Glasgow, he’s played for Sunderland, Galatasaray and now Lyon where he is getting ready to embark on a third season.
He’s a regular starter for Les Gones and should see some action on Saturday night – probably in a tantalising battle against Odsonne Edouard.
Many Celtic fans will still look out for Denayer’s fortunes. He’s well liked among the support.
With him and Dembele in action together, many Hoops fans may be routing for the Ligue 1 side when the Champions League restarts early next month.