The 25-year-old is currently recovering from a knee ligament injury that he sustained during Sunday’s 2-1 win over Aston Villa.
A club statement said: “Newcastle United can confirm that Leon Best has sustained medial ligament damage to his left knee.
“The striker was forced off in the early stages of Sunday’s home victory over Aston Villa having picked up an injury while trying to get a shot away.
“After being assessed by the club’s medical staff, Best underwent a scan on Tuesday and will be out for a number of weeks.”