The veteran forward is suffering with flu-like symptoms and trained away from his team-mates on Saturday.
Totti will now undergo a late test before Sunday's encounter at Stadio Sant'Elia.
Speaking at his pre-match news conference, Garcia said: "Totti trained on his own. He's got flu-like symptoms and we'll have to see if he's able to play."
If Totti is unavailable the 38-year-old will add to a growing list of absentees that includes recent signing Victor Ibarbo and Kevin Strootman.
Ibarbo, who was carrying an injury to his left calf before hurting his right on his debut in Tuesday's Coppa Italia defeat to Fiorentina, is set to see a specialist in Barcelona.
Garcia has called on the rest of his squad to work even harder to cope with the injury problems.
"Ibarbo? It's not the same calf muscle he's injured. I think it's just a question of bad luck," Garcia added.
"Ibarbo needs to have his patellar ligament looked at, that's why he's going to Barcelona for a check-up.
"We'll do the best we can [against Cagliari] with the players who are available. They'll all have to go the extra mile. I'm looking at the positives. Soon I'll have more options to choose from for the run-in."
Roma are hoping to end a run of four straight league draws at Cagliari in a bid to close the seven-point gap to Serie A leaders Juventus.
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