Portsmouth coaches Paul Groves and David Coles have left the club to join Avram Grant's backroom team at West Ham United.
Ian Woan and Guy Whittingham will assist Portsmouth manager Steve Cotterill in first-team coaching duties while a replacement for Groves is considered.
John Keeley, meanwhile, will step up from Pompey's academy to replace Coles as first-team goalkeeping coach.
Portsmouth chief executive David Lampitt said: "We are sorry to lose both Paul and David to West Ham, but understand the offer to continue working in the Premier League was difficult to refuse.
"I would personally like to thank them both for the excellent jobs they have done at the club and wish them well for the future."
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