The 20-year-old arrived at Fratton Park temporarily from Manchester City in the summer.
And his immense potential has been there for all to see this season as he’s established himself as the club’s first-choice goalkeeper – making 35 appearances in all competitions to date.
As a result, his market value has already risen by £500,000 under the guidance of Danny Cowley.
But where does that shoot up in price rank across every League One loan deal ever?
Well, thanks to transfermarkt.com’s transfer values, we can find out...
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1. Wojciech Szczesny - £383k increase
Loan club: Brentford (2009-10) Parent club: Arsenal Appearances: 28 Current club: Juventus Picture: Gabriele Maltinti/Getty Images Photo: Gabriele Maltinti
2. Liam Moore - £405k increase
Loan club: Brentford (2011-12) Parent club: Leicester Appearances: 22 Current club: Stoke (on loan from Reading) Picture: Nathan Stirk/Getty Images) Photo: Nathan Stirk
3. Pim Balkestein - £405k increase
Loan club: Brentford (2010-12) Parent club: Ipswich Appearances: 32 Current club: SV Elversberg Picture: Christopher Lee/Getty Images Photo: Christopher Lee
4. Jamie McMaster - £450k increase
Loan club: Swindon (2004-05) Parent club: Leeds Appearances: 4 Current club: Retired Picture: Phil Walter/Getty Images Photo: Phil Walter