Harlequins fly half Rory Clegg, 20, returns after kicking three penalties to clinch last weekend's 14-11 win over Worcester Warriors while Leicester Tigers lock Calum Green, 19, won rave reviews for his part in the 35-19 victory against London Irish.
Clegg, the starting fly half for England in last year's IRB Junior World Championship final, comes into in the back division with wing Sam Smith (Harlequins), full back Tom Catterick (Newcastle Falcons) and three uncapped players in centres Mark Atkinson (Sale Sharks), Andrew Forsyth (Leicester Tigers), wing Marcus Watson (London Irish).
Up front, flankers Jamie Gibson and Will Welch return from Premiership duty with London Irish and Newcastle respectively, and 130kg tight head prop Mako Vunipola (Bristol Rugby) will be in a matchday squad for the first time at this level.
"It's good to have guys returning from Premiership clubs and they come back to us having played well," said Mapletoft.
"It's also a great opportunity for the likes of Mark Atkinson and Andrew Forsyth to do well and for wing Marcus Watson coming back from injury.
"We haven't played particularly well in the backs and we need to incorporate some better decision making and more accuracy into what we're doing.
"The forwards have given us a platform and the expectation is there that on a good night we can really rattle the scoreboard, but making changes because of injuries and unavailabilities has made it difficult to put combinations together."
England won the opening two games of the Under 20 RBS 6 Nations against Wales (33-16) and Italy (16-10) and are tied at the top of the table with Ireland and Wales.
England U20 squad
Arthur Ellis (London Wasps), Jamie George (Saracens), Jamie Gibson (London Irish), Calum Green (Leicester Tigers), Lee Imiolek (Sale Sharks), Joe Marler (Harlequins), Charlie Matthews (Harlequins), Jacob Rowan (Leeds Carnegie), Mako Vunipola (Bristol Rugby), Will Welch (Newcastle Falcons), Jackson Wray (Saracens), Danny Wright (Gloucester Rugby)
Mark Atkinson (Sale Sharks), Tom Casson (Harlequins), Tom Catterick (Newcastle Falcons), Rory Clegg (Harlequins), Sam Harrison (Leicester Tigers), Andrew Forsyth (Leicester Tigers), Jonathan Joseph (London Irish), Jordi Pasqualin (Gloucester Rugby), Sam Smith (Harlequins), Marcus Watson (London Irish)