Terry McPhillips admits Mark Howard could be out of action for anywhere between six and 12 months after the goalkeeper begins his recovery from a ruptured Achilles.
The 32-year-old suffered the blow during the 3-0 defeat at Burton Albion last month.
The shot stopper was immediately ruled out for the remainder of the season and underwent successful surgery the following week.
While McPhillips has revealed Howard is making good progress, the Pool boss remained cautious when asked about the prospect of the keeper being fit for the start of next season.
“I think with his injury it can be six months, it can be nine months or it can be 12 months," McPhillips told The Gazette.
“What I can say is that everything has been spot on so far. The surgery went well and everyone is really pleased with how it’s gone.
“Knowing Mark and how professional he is and how he lives his life I wouldn’t be surprised if it was the six months rather than 12.”
One man to recently return from an injury lay-off was Ollie Turton, who made his first start in a month in last week's 2-2 draw at Luton Town.
It was the right-back's first appearance since suffering a hamstring injury in the homecoming clash against Southend United.
“He really did grow into the game," McPhillips said of Turton's display at Kenilworth Road.
“He was disappointed with his defending for the goal but that lad (Kazenga LuaLua) is a top player. He just got turned and beaten and the lad got the cross in.
“Ollie is as honest as the day is long.If you look back at last week’s game he makes a vital late tackle.
“He’s a top pro, he’s a great lad and it’s great to have him back in the team.”