As is often the case when footballers leave a club, supporters often like to keep an eye on former players and watch how their careers progress - particularly those stepping into management.
Celtic and Rangers fans are no different in that respect as they track how players are faring at their new clubs, whether it be loan signings or players who have been sold on.
The two Glasgow giants currently have 16 ex-players sitting in the managerial hot seat at clubs spanning the length and breadth of the UK this season. Eight former Hoops and Light Blues stars of years gone by who have represented the clubs at some level and even won domestic honours during their time in Glasgow make up the following list.
From Gary Caldwell in Southwest England to newly-appointed Duncan Ferguson in the Scottish Highlands, we take a look at those former Old Firm players who are now gaffers:
5. Duncan Ferguson - Inverness CT
Moved to Rangers for a then British record transfer fee of £4m in 1993 from Dundee United. Earned legendary status at Everton and had two separate spells as interim boss at Goodison before striking out on his own with League One Forest Green Rovers. Now back in Scottish football after heading to the Highlands. | Getty Images
6. Malky Mackay - Ross County
Part of the legendary Hoops squad that stopped Rangers’ bid for ten in a row. Retired in 2008 and became manager of Watford the following year. Reached the Premier League with Cardiff City and had a spell at Wigan before working for the SFA as its performance director. Now in his third season with the Dingwall-based club. | Getty Images
7. Frank de Boer - Al Jazira
A well-respected global icon and Champions League winner who starred for Ajax and Barcelona before later having a brief spell at Ibrox in 2004. Previously head coach of the Dutch National Team, he is currently boss of UAE Pro league club Al Jazira. | AFP via Getty Images
8. Tony Mowbray - Sunderland
Spent four seasons at Celtic in the barren 90s era and wasn’t able to win any silverware. Successful spells in charge of Hibernian and West Brom led to him being appointed Celtic boss in 2009. An underwhelming spell saw him depart of Middlesbrough. Has since filled roles with Coventry City, Blackburn Rovers and Sunderland. A highly regarded figure in English football. | Getty Images