With little more than a week before the opening the ceremony, the 31-year-old runner said he will make a decision "further down the line".
His comment came as organisers confirmed there are still tickets available for some of the most high-profile events - including the 5000m Farah is supposed to be competing in.
He is due to run for England in the event, as well as the 10,000m, but was forced to pull out of last weekend's Diamond League event at Hampden Park because of illness.
Asked if he was going to be fit for the Games, he said: "It's a good question. I don't know. Hopefully I should be good. I have missed a bit of training, but we'll make a decision further down the line."
Farah was admitted to hospital in the United States with abdominal pains at the start of the month and has had further tests in the United Kingdom.
He says team doctors have given him the all-clear to return to training but has not confirmed whether he will run in his next scheduled race, over two miles, at the London Anniversary Games on Sunday.
Other stars who have decided not to take part in the Games include cyclist Mark Cavendish, who was injured during the Tour de France this month, and heptathlete Jessica Ennis-Hill, who is taking time out to have a baby.
Meanwhile, on the Glasgow 2014 ticketing website, customers can still buy seats at a number of medal sessions, including the men's and women's 100m finals. However, organisers said the unsold seats were a small part of the overall capacity.
A spokeswoman added: "Glasgow 2014 has already sold more than 1.1 million tickets, making this the most successful event in Scottish sporting history.
"As is normal practice in the final run-up to a major multi-sports games, opportunities will become available across the sports programme as venues reach their final stages of configuration."