"Aaron Cresswell, Havard Nordtveit and Jonathan Calleri have all returned to full training," said Stijn Vandenbroucke, West Ham's head of Medical and Sports Science.
"Gokhan injured his quadriceps in training during the international break and is going to be out for 4-6 weeks."
Tore will join club's record signing Andre Ayew, striker Andy Carroll and left back Arthur Masuaku on the treatment table.
West Ham, who finished seventh last season, are 18th in the Premier League standings after seven matches and will be aiming to secure a first league win since August when they travel to London rivals Crystal Palace on Saturday.
(Reporting by Shravanth Vijayakumar in Bengaluru; Editing by John O'Brien)
