Rangers manager Mark Warburton could turn to Philippe Senderos in his search for a fourth centre-back after a move for Aston Villa's Joleon Lescott fell through.
On Thursday, Warburton had expressed optimism about the chance of signing Lescott, and the defender subsequently visited Glasgow.
But the move collapsed on Friday, with Rangers citing family reasons as the reason Lescott would not be signing.
Villa boss Roberto Di Matteo said: "He passed a medical and everything. They didn't agree personal terms so the move has fallen through and he is back with us now.
"It [Lescott leaving] depends on what solution he will find, one which suits the club and the player.