Centre-back and skipper Mark Beevers is the oldest at 31 with teenage defender Ronnie Edwards the youngest of three 18 year-olds. Aaron Powell and Ricky-Jade Jones are also 18.
Here are some facts about the men most likely to be entrusted with keeping Posh in the Championship...
CHRISTY PYM: Age: 26. App: 87 Goals: 0. FACT: When goalkeeper Christy missed the League One win at Charlton last April because of injury it ended a run of 74 consecutive Football League appearances for Posh. He returned for the final game of the season.
RONNIE EDWARDS. Age: 18. Apps 6. Goals 0. FACTS: Defender Ronnie was called in to an England Under 19 training camp last season. He captained his previous club Barnet to a Bees record run to the third round of the FA Youth Cup before joining Posh aged 17.
DAN BUTLER. Age: 26. App: 81 Goals: 3. Facts: When at Newport County, defender Dan won the EFL ‘Player in the Community Award’ two seasons in a row. He played in Newport’s League Two play-off final defeat to Tranmere in 2019 before joining Posh.
NATHAN THOMPSON. Age: 30. App 62. Goals 2. FACTS: Defender Nathan won back-to-back player of the season awards when at Swindon (2012-13 & 2013-14). He skippered Swindon in the League One play-off final against Preston in 2015, but was carried off after five minutes.