Northampton manager Chris Wilder has confirmed interest from Premier League and Championship clubs for Ivan Toney.
Notts County full-back Jordan Cranston has left the club by mutual consent.
The Scot claimed his 13th league title with United this season but has already started his preparations to defend that crown next term.
He is convinced he has the players at the club to provide a solid foundation for the next five years but is still keen to add quality where possible.
And despite not having the spending power enjoyed by the likes of Manchester City or Chelsea, Ferguson is confident that United can be competitive in the summer transfer window.
"You have to look at the structure of the club at present, in terms of the number of first-team players we have at 23 or under," Ferguson said in his column for Inside United.
"David De Gea, Rafael, Phil Jones, Chris Smalling, Alex Buttner, Nick Powell, Tom Cleverley and Danny Welbeck, Shinji Kagawa and Chicharito are 24. Jonny Evans is 25 and Wayne Rooney is hitting his peak at 27.
"Older players like Ryan Giggs, Paul Scholes and Rio Ferdinand may be coming towards the end of their careers, but these younger players are the foundation for the next five or six years, irrespective of the players breaking through, like Adnan Januzaj, the Belgian boy, who's really looking very good.
"Hopefully the players we bring into the club in the next year or so will be of the quality we need. We're competitive in the market - we're not Chelsea or Manchester City in terms of money but we're competitive.
"We've been doing a bit of work on that over the last three or four months, targeting who the players are that we feel could enhance us, make us better or help us maintain the level we're at."