Kolisi told South African media at a pre-Lipovitan D Rugby Championship Springbok camp in Pretoria that his rehabilitation was going well after surgery last month on a knee ligament injury.
A similar injury occurred before the 2019 World Cup, where South Africa beat England in the final to join the All Blacks as three-time event winners. Kolisi recovered to play two warm-up games ahead of that event.
But it will likely be the second-round game against Romania before he is ready to play in France.
"It sucks; it's not nice to be in this position. But the nice thing is, I have been here before with both coach Jacques [Nienaber] and Rassie [Erasmus]. And it's a good feeling to be supported like this. The medical team is working really hard.
"I feel good. Each day is different and I am taking it day by day. The nice thing is that I have been here before. I have been through this, so I know that I've got to take each day [as it comes]. But I am confident that I will be fine."
Being involved with the camp has helped him remain positive in his recovery, and he has been able to talk with other players who have knee injuries, Handre Pollard, RG Snyman and Pieter-Steph du Toit.
"Rehab is going well. I am working hard. It is great to be working in the team environment. It helps a lot on the mental side to see the work happening. If I wasn't here, I would miss out on a lot that the group is doing.