document: The 24-year-old sustained the injury to his right knee during last week's EFL Cup fourth-round win over Tottenham.
  It is not the same knee in which he suffered an anterior cruciate ligament injury in October 2015 that sidelined him for seven months.
  "To say we are gutted would be an understatement," said Liverpool boss Jurgen Klopp.
  "He is such a great boy and has worked so hard that he deserves better luck than this.
  "It is typical of Danny's personality, on and off the pitch, that he picked up this injury to his knee when courageously trying to win the ball back for his team by making a tackle.
  "But it is this same personality that means he will come back as good and as strong from this latest setback as he has done in the past.
  "He is mentally strong, physically strong and will have the very best treatment and rehab possible to make sure when he returns he is ready to play for us at the level we know he is capable of."
  England international Ings will have surgery in London on Tuesday.
  He joined Liverpool from Burnley in June 2015 for a fee that was later set at £8m by a tribunal.
  However, injuries have limited him to just 11 appearances for the Reds since then, in which he has scored four times.
  He made his one and only England appearance as a substitute in the 3-0 Euro 2016 qualifier in Lithuania in October 2015, shortly before he suffered his anterior cruciate ligament injury.
summary: Liverpool striker Danny Ings will be out for up to nine months with a knee injury that requires surgery.