Mustapha, 18, made a big impact as a substitute for Yorkshire Academy in their 30-22 loss to Australian Schoolboys three days ago.
That came weeks after he produced an eye-catching performance for Featherstone Rovers, on a one-game emergency loan, when they beat Leigh Centurions in the Betfred Championship Shield final.
Rhinos Under-19s coach Rob Burrow admits to being an admirer of the Nigeria-born prop who grew up in Leeds and played junior rugby for Hunslet Warriors.
“A lot of people in the Yorkshire team would have had a reputation going into that game and he is starting to develop a reputation now,” Burrow said.
“At the club, [academy assistant-coach] Jonny Wainhouse and I totally rate him as a player and his performances are starting to get the recognition he deserves.
“There are not many people like him.
“He’s not the biggest, but players who can do the stuff he does are few and far between.
“He wants to knock people over in defence and trample on people in attack.
“In that respect he is an old-fashioned prop and I am sure, on that performance, he has put himself forward for the England team.”
England Academy face the Aussies in Leigh next Saturday before a second Test at Emerald Headingley six days later.
Mustapha is preparing for his final year in Rhinos’ Under-19s and will have to either earn a first-team contract for 2020 or move on.
Burrow said: “When he came into the scholarship he couldn’t catch or do anything, but when it got physical he started flattening people and his skill has come on in leaps and bounds.
“He is progressing well and Kev [Sinfield, Rhinos’ director of rugby] and Dave [Furner’ Leeds’ coach] were there on Wednesday and they will have taken note of his performance.”
Mustapha missed the start of the 2018 season after picking up an eight-match ban, but Burrow stressed: “He is a genuinely nice lad.
“He is tough, but there’s no malice in him. I believe he can have a career in the game. I am a big fan of him.”