Leicester boss Claudio Ranieri hopes to have Kasper Schmeichel back before Christmas to help ease the Foxes' relegation fears.
The Denmark international has been out for a month after breaking his hand in the Foxes' goalless Champions League draw in Copenhagen.
Replacement Ron-Robert Zieler has conceded 16 goals in eight games and has kept just one clean sheet to leave Leicester two points above the Premier League relegation zone.
Schmeichel, who was also missing with a hernia problem earlier in the season, was due to be out for up to six weeks but is training and has rejoined the goalkeepers after previously working as an outfield player.
Leicester have won just one point in three league games since his hand injury and, as they head to bottom-of-the-table Sunderland tomorrow, Ranieri is keen to see the goalkeeper fit again.
He said: "I hope before Christmas Day he'll be ready. It depends on him and the surgeon but his fitness is getting better. He is working on a normal training session, separately."
Ranieri refused to be drawn on talk of a January move for £14m-rated Genk midfielder Wilfred Ndidi.