Day signed his first professional deal at the start of last season
Peterborough United have signed Rushden & Diamonds goalkeeper Joe Day for an undisclosed fee.
The 20-year-old cannot feature for Posh until the transfer window re-opens in the summer, but he will begin training with the club.
An England C international, Day has made 35 appearances for Blue Square Bet Premier Rushden.
"He is one for the future, but he has a lot of raw talent," said Posh goalkeeper coach Barry Richardson.
A Rushden statement added: "Although Rushden & Diamonds are sorry to lose a fantastic home-grown player, the progression for Joe that Peterborough can offer is a fantastic opportunity and we wish both Joe and Peterborough every success in the future."
Day started at Diamonds in the under-17 set-up and made his competitive debut in a 1-0 win at Wrexham in April 2010.
He has been first choice for Justin Edinburgh's side this term, keeping seven clean sheets.
