John Tait asked a friend to beat him up and then lay bleeding on the floor of the Scotmid store in Edinburgh as he waited for the police to arrive.
Tait told the authorities that he had been on duty in the store when a man broke in and stole more than £3,300 from the safe. Suspicions were raised when the store rota showed Tait, a trainee supervisor, was not scheduled to work on that day.
CCTV footage later showed Tait unlocking the store and entering with his accomplice Christopher McGirr.
The pair later admitted concocting a plan to stage a fake robbery in order to pay back gambling debts. Tait also admitted to having stolen another £3,000 from the safe four days before.
Handing down the sentence, Sheriff Michael O'Grady told Tait that he had committed a "gross breach of trust". He added: "In my view, it's wholly appropriate that these crimes should be punished by a prison sentence."
McGirr was also jailed for eight months.