The 29-year-old Italy international has made only 10 appearances for the club to date this term because of a combination of groin and ankle injuries, and it is recurrence of his ankle problem which is currently giving cause for concern.
Head coach Gus Poyet told the Sunderland Echo: "It doesn't look good
We are reassessing, but we will get a full update [this] week.
"It is the same injury he had before
I don't want to go further, but it's not good
I hope the specialist opinion in the week is positive."
Giaccherini, who joined the club in a £6.5million switch from Juventus in July 2013, sat out three months of the season before returning as a substitute in the 3-1 Barclays Premier League defeat to Hull at the Stadium of Light on Boxing Day.
However, his comeback amounted to just six games after he was injured once again during the 3-1 FA Cup fourth-round replay victory at Fulham on February 3, one of just four starts he has made this season.
His latest spell on the sidelines comes as £10million summer signing Jack Rodwell too battles for fitness having not reappeared since his red card against Fulham in the first game on January 24 after damaging a calf muscle.
Poyet was at least able to welcome Lee Cattermole back to the side after a 10-game absence for Saturday's frustrating 0-0 draw with West Brom.
The Uruguayan said: "At any level, you need different characters and in special moments, you need certain ones and I think Lee is one of them.
"He is very important in difficult moments."
Source : PA
Source: PA