is expected to miss the Republic of Ireland's World Cup play-off games.
The 34-year-old Burnley forward is currently sidelined by a knee problem.
It is understood he will not have recovered in time for the play-offs, the first legs of which will be staged between November 9 and 11, with the return fixtures then taking place over the following three days.
According to reports, Walters will be out of action until at least Christmas.
As well as sitting out the Republic's matches against Wales on Monday and Moldova last week, Walters, who Burnley signed from Stoke over the summer, has not been involved in the Clarets' last two Premier League games.