Crooks, a City youth product who played 73 games for the first team between 1994 and 2001, has joined the elite team of the RAF Regiment.
The Wakefield-born 33-year-old joined the regiment in 2010 and graduated to leading aircraftman last month.
New team: Former defender Crooks (left) helped City gain two promotions
Wakefield-born Crooks, 33, played for a number of other clubs including Barnsley, Bradford and Rochdale before he joined the regiment as a gunner in 2009.
He graduated to Leading Aircraftman a few weeks ago and is currently on the training range ahead of moving on to 1 Squadron RAF Regiment at RAF Honington in Suffolk. From there he will embark on his first tour of Afghanistan at the beginning of next year.
Comparing life as a professional footballer and a gunner, he said: 'Both roles are about working as a team, being there for your team-mates and moving forward as a team.
Then and now: Crooks in his Man City days (left) and in more camouflaged times
'You have to be mentally and physically fit for both roles, but you train as a professional footballer for 90 minutes so the training is a lot more explosive, whereas being a gunner you have to be robust and have a lot more stamina as you are carrying heavy weight over longer distances and over longer days and nights.
'You train all week to prepare for the Saturday game and put everything that you've trained for into that game and it's exactly the same as this.
'I have done my training and am now really looking forward to putting it into practice.'
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