 Thatcher will decide between Pompey and Man City |
Portsmouth will discover on Monday whether Leicester defender Ben Thatcher will join them or Manchester City. City looked to have made a successful last-minute bid to snatch Thatcher away from Pompey.
But Thatcher has agreed to let both clubs know his decision after thinking things over during the weekend.
Chairman Milan Mandaric said: "Having said he would be a Portsmouth player, we'd be very disappointed if it didn't turn out that way."
Thatcher is free to leave the Foxes after both Pompey and City agreed to the �100,000 trigger fee set in the 28-year-old's contract in the event of relegation from the Premiership.
Leicester have already lost Paul Dickov to Blackburn in similar circumstances.
Thatcher began his career at Millwall before moving to Wimbledon in July 1996 for �1.7m.
He made 82 appearances in four years with the Dons, and cost Tottenham �5m when he moved to White Hart Lane in July 2000.
Injuries limited his appearances for Spurs and he left on a free transfer in July 2003 to join Leicester.