Loan signings are forbidden but unattached players can still move on free transfers, meaning the likes of Preston, Wigan and Bristol City could strengthen.
The former Newcastle United, Wigan Athletic and Aston Villa winger's move to Nantes has collapsed.
The 30-year-old had a torrid time at Aston Villa, having previously starred for Newcastle, Wigan and even the French national team.
Diame joined the Magpies from Hull City earlier this summer.
Pienaar is thought to have linked up with his former Everton manager David Moyes to train at the Stadium of Light.
The former Aston Villa playmaker has been on trial at the Stadium of Light since the beginning of the summer.
The ex-Aston Villa man has been training with Sunderland.
Sunderland fans have been impressed by the performance of former Aston Villa man Charles N'Zogbia.
Sunderland beat Rotherham 2-1 today, with trialist Charles N'Zogbia grabbing a goal.
The former Aston Villa winger does not however look to be impressing the Sunderland hierarchy.
Philippe Senderos, Joe Cole, Carles Gil and Charles N'Zogbia are all squad members who will have to raise their game for first-team football.
The 30-year-old defender was left off the club's 25-man Premier League squad after failing to see any first-team action since Tim Sherwood's appointment.
Tottenham's Aaron Lennon has emerged as a target for Tim Sherwood's Aston Villa.