The Stags boss landed 20-year-old D"Laryea, 20, for a nominal fee from Manchester City while Laurence Wilson, 19, joins on a one-month loan from Everton.
Speaking in todays Nottingham Evening Post, Shirtliff said "Jonathan is one for the future. He is an athletic type of lad and he proved what a good player he was when he was here previously - we"ve certainly missed him.
"Laurence has pace and likes to get forward down the left. He"s tough and gets stuck in and that"s the type of player I want.
"I"ve seen him in Everton"s reserves and made a couple of enquiries about him. It"s a good deal for both parties."