The twice Grand Slam winner retired in the first set of her Cincinnati quarter-final match against Iga Swiatek on August 20 with an ankle problem.
"I'm quite confident with the decision we are making each day how to practice, what to do, and especially what can happen worst-case scenario. So all these things I feel quite confident," Rybakina told reporters at Flushing Meadows on Saturday.
"I just feel like it's just few more days and I should be very fine."
Kazakhstan's Rybakina, 27, said it was painful to walk for a couple of days after suffering the injury, but she is glad with how her recovery process is going.
"We will see what's gonna happen in the next few days, but for now it's been well," she said. "I always want to go on court when I'm 100% sure, and it's the last slam of the year, so I think everyone will want to try to compete."
Rybakina is set to open her U.S. Open campaign against American Thea Frodin.