Celtic have had many players arrive at the club on loan deals over the years such as Jonjoe Kenny, Diego Laxalt and Mohammed Elyounoussi among many others.
While most players that come on loan end up going back to their parent clubs, one player that the Hoops would presumably now be regretting not securing a permanent deal for is defender Jason Denayer.
Having arrived at the Parkhead club on loan from Manchester City back in the 2014 summer transfer window, the centre-back ended up making 44 appearances in total during his time in Scotland across all competitions, chipping in with six goals and two assists along the way, showing how useful he was in front of goal.
After leaving Celtic, the Belgian had loan spells with Galatasaray and Sunderland before eventually bringing his time as a City player to an end in the summer of 2018 when he joined French club Olympique Lyon in a deal worth a reported fee of €13.5m (£11.4m).
Since then, the 26-year-old has gone on to make 136 appearances for Lyon across all competitions with eight goals and two assists to his name.
Back in October 2014 when the former City defender was making a name for himself with the Hoops, Transfermarkt had his market value listed as £450k, whereas it now stands at £18m, highlighting a huge increase of 3900% based on what he’s done in his other loan spells and in France with his current club.
Labelled as a “powerful” player in terms of winning his defensive duels by Lyon’s recruitment chief Florian Maurice, Denayer has certainly found his feet after such a long but ultimately uninspiring time with the current Premier League leaders.
Taking all of this into account and with the benefit of hindsight, it could be seen as a big mistake from Peter Lawwell to not secure a permanent deal for Denayer after his loan spell in Scotland as he could have gone on to be a stalwart figure for the Hoops at the back.
Moving forward, with the defender’s current contract at the French club set to expire at the end of the season, it’ll be interesting to see whether or not Celtic would be inclined to try and bring the Belgium international back to Scotland in the summer and whether he’d be open for the move or not.