Lund and Askins are defenders, while Whitehouse and Ferguson both play in midfield. They are all expected to put pen to paper on deals shortly.
First-team manager Paul Dickov told the club's official website: "To have players coming through the youth set-up at any club is vitally important to the long-term future of the football club. We were delighted to give the four players the opportunity.
"The lads that have come through, all of them, have something to offer. When and where is now up to me, but if they show the right endeavour and application, they will have the same chance as everybody else."