Khan is thought to be on the verge of stepping up again
Kent seamer Amjad Khan has been told he is still in the England frame after being included in the top category of players in the performance squads.
Khan, 28, who played one Test on the tour of the West Indies in March, is among four players identified as being closest to making the senior side.
Lancashire's Stephen Moore, Hampshire's Michael Carberry and Durham's Mark Davies are the others in category A.
The quartet will receive individual support programmes.
A further 37 players have also been named in the performance squads with 10 in category 'B', 22 in 'C' and an additional five in the fast-bowling programme.
Players in group 'B' have significant first-class experience and are perceived to be one to three years away from the England team while 'C' players are generally younger with less experience.
England and Wales Cricket Board performance director David Parsons said: "To see eight players who were part of the England Performance Programme last winter selected for England's tour of South Africa next month is a good indication of the importance of the programme for a player's development.
"With players like Eoin Morgan, Jonathan Trott and Graham Onions having made an immediate impact in the international arena this summer, having spent time with EPP and England Lions squads recently, we are keen to identify other players within County Cricket who can make a difference to the full England side."
England Performance Programme Squads
Category A players (players perceived closest to graduating into the England team and who have been part of the programme and Lions teams in recent years):
Mark Davies (Durham), Amjad Khan (Kent), Stephen Moore (Lancashire), Michael Carberry (Hampshire).
Category B players (experience of first-class cricket and perceived to be one-three years away from the England team):
Steven Finn (Middlesex), Andrew Gale (Yorkshire), Rory Hamilton-Brown (Sussex), Chris Jordan (Surrey), Chris Nash (Sussex), Joe Sayers (Yorkshire), Ajmal Shahzad (Yorkshire), James Taylor (Leicestershire), David Wainwright (Yorkshire), Chris Woakes (Warwickshire).
Category C players (younger players with less first-class county experience, many of whom have been part of the ECB elite player development programme):
Jonathan Bairstow (Yorkshire), Vikram Banerjee (Gloucestershire), Keith Barker (Warwickshire), William Beer (Sussex), Alex Blake (Kent), Andy Carter (Nottinghamshire), Liam Dawson (Hampshire), Luke Fletcher (Nottinghamshire), Billy Godleman (Essex), Alex Hales (Nottinghamshire), Richard Johnson (Warwickshire), Richard Jones (Worcestershire), Adam Lyth (Yorkshire), Jake Mickleburgh (Essex), Sam Northeast (Kent), Ollie Rayner (Sussex), Ian Saxelby (Gloucestershire), John Simpson (Middlesex), Tom Smith (Sussex), Max Waller (Somerset), Adam Wheater (Essex), David Willey (Northamptonshire).
Fast bowling programme:
Jade Dernbach (Surrey), David Griffiths (Hampshire), James Harris (Glamorgan), Stuart Meaker (Surrey), Boyd Rankin (Warwickshire)