Hyam, 17, signed a three-year contract with the Royals on Monday and is hoping to play some part in the Under-21s side's clash with QPR.
He told the club's official website: "I'm a centre-half, I like to win my headers, defend well and score from set-pieces as well - which is a bonus. I'm delighted to have signed - this is what all the hard work is for.
"Hopefully I'll be involved in the Under-21s game, so it will be nice for supporters to come and watch us play. It would be a good opportunity to show the fans what I've got."