The club posted a video on Twitter of Navas becoming the victim of a faked "kidnap", bundled into the back of a auto with a bag over his head before being driven to the stadium.
The Spain global joined the Sky Blues in 2013 from Sevilla for £14.9 million but was released by earlier in the summer.
Sevilla pulled in close to £15 million when offloading Navas to City, but have brought him back without having to pay a fee.More news: Motorola set to launch Moto G5S Plus soon
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Back at Sevilla, where he came through the youth academy and began his senior career, Navas could well thrive.
His four seasons in England delivered further success, with Premier League and League Cup triumphs toasted, but Navas struggled to produce his best form at City.
While at City, Navas made 173 appearances for City, scoring eight goals, but played just 24 league games last season.
But instead of sharing the standard picture of him in his new club's shirt, barmy Sevilla chiefs put out a video of the speedy winger being kidnapped by hooded thugs and then released at their Ramon Sanchez Pizjuan stadium.