The 34-year-old picked up a muscle strain in the 2-1 win over Siena and is now set to miss half of the Nerazzurri's remaining Serie A fixtures
The Argentina international was forced off seven minutes before the interval in Wednesday's 2-1 win over Siena and subsequent scans have revealed a muscle strain in his right leg.
After picking up a booking at San Siro, Samuel would have missed this weekend's meeting with Udinese anyway, but now the centre-back will also be unavailable for the clashes with Fiorentina and Cesena.
The 34-year-old has been a mainstay of the Nerazzurri defence since arriving at the Giuseppe Meazza from Real Madrid in 2005 and his absence is a major blow for a side which has not given up hope of securing a place in next season's Champions League.
Inter are currently seventh in Serie A but are now just six points behind third-placed Lazio.