MARTIN O'NEILL will overhaul Sunderland's academy and reserve-team squads this summer in an attempt to stamp his mark on the long-term future of the club.

As well as targeting a number of additions to his senior squad, O'Neill is keen to strengthen the levels below the first team.

Jack Colback is the only player to have progressed from the academy into the first team in recent seasons – James McClean was bought in from Derry City rather than developed at the Academy of Light – and O'Neill is determined to improve the quality of players attempting to break into the senior set-up.

Sunderland revealed their released list on Saturday, and as expected the headlines were hogged by the departure of Craig Gordon, who will be offered the opportunity to join West Ham United following the Hammers' victory in this weekend's Championship play-off final with Blackpool.

West Ham are also set to make a £1.5m offer for Black Cats midfielder Ahmed Elmohamady in the next few days.

However, as well as releasing Gordon, Sunderland have also failed to renew the contracts of eight other players from the fringe of their squad.

Fellow goalkeepers Trevor Carson and Lewis King are departing, along with defenders Liam Bagnall and Jordon Lavendar, midfielders James Brace and Brett Elliott, and strikers Oumare Tounkara and Jordan Cook, who made a couple of first-team appearances under Steve Bruce.

Sunderland officials also confirmed that last season's three loan signings – Nicklas Bendtner, Wayne Bridge and Sotirios Kyrgiakos – will not be returning to Wearside.

The clear-out has created space for some additions, and O'Neill, who is aware of Grant Holt's growing unhappiness with life at Norwich City, is expected to recruit a number of promising youngsters this summer.

The Northern Irishman has noted Newcastle United's success at attracting talented teenagers from right across Europe, and is hoping to improve Sunderland's record of recruiting junior talent.

As well as releasing players at the weekend, the Black Cats also handed a professional deal to three players from Kevin Ball's youth team.

Defenders Anthony Callaghan and Connor Oliver join North Shields-born striker Jordan Laidler in signing their first professional contracts.