Sturridge, 26, only made seven league starts last season because of injuries, and has not played at all since April.
The England forward is back in training, but will not be available for Saturday's game at Manchester United.
"He looked really sharp, probably the best he's looked fitness-wise for 18 months," said Rodgers.
Sturridge scored 24 goals in 33 appearances in the 2013-14 season as Liverpool finished second in the league, but was blighted by injuries last term.
The former Chelsea and Manchester City striker spent five months out with a thigh problem sustained on international duty, which was then followed by a calf strain.
He then had an operation on his hip in May, and spent the summer undergoing rehabilitation in the United States.
"I can never say that he is over the worst of his injuries because I don't want to sit here and something happens in a couple of months' time," added Rodgers.
"I can only look at what I see and from my experiences in the past I don't want to put any timeline on him coming back."
Daniel Sturridge is the fittest he has been for 18 months, says Liverpool manager Brendan Rodgers, as the injured striker closes in on a return.