Inter have confirmed Marcelo Brozovic sustained a sprained ankle in the 1-1 Serie A draw with Lecce on Sunday.
The midfielder was substituted with eight minutes of normal time remaining at the Via Del Mare after a clash with Alessandro Deiola.
The Croatia international had an MRI scan on Tuesday, with Inter confirming: "The tests revealed a sprain to his left ankle. The player will be assessed on a day-by-day basis."
Brozovic's injury is said to be part of the reason Inter have stepped up plans to sign Tottenham midfielder Christian Eriksen this month.
Sporting director Piero Ausilio said on Monday that a bid for the playmaker had been lodged, although Spurs boss Jose Mourinho intends to have Eriksen in his squad for Wednesday's Premier League game against Norwich City.
Brozovic has played in all but one of Inter's 27 matches in all competitions this season, scoring twice.
Antonio Conte's side are second in Serie A, four points behind champions Juventus.