Pakistan off-spinner Saqlain Mushtaq is to undergo a second knee operation and has been told he will need to rest for several months to recover from a career threatening injury.

The 28-year-old had surgery on his left knee earlier this year and will have medical treatment on his right knee in October that will put him out of action for six months.

"It is disappointing to be in such a situation. But the doctors say that if I don't get proper and permanent treatment, my career could come to an abrupt end," Mushtaq told Reuters on Tuesday.

Mushtaq is the second Pakistani cricketer this month to be ruled out for a long period because of fitness problems.

Last week young paceman Umar Gul was told he could not play for at least six months because of a stress fracture in his back.

Mushtaq said his erratic form in his last international appearance had been the result of his knee injuries.

In that match in March, Mushtaq conceded 204 runs for just one wicket in the first Test against India in Multan

Selected as the Wisden cricketer of the year in 2000, Mushtaq has been in poor form for Pakistan and English county Surrey this year despite his impressive haul of 208 Test wickets and 288 one-day international victims.