The regulator said without a licence, any activity completed on Sorare.com by consumers in Great Britain is outside the regulations a licensed operator should comply with, such as player protection rules.
As such, the Commission said consumers should consider this information before they sign up to and interact with Sorare.com.
The Commission added it would carry out further enquiries to establish whether Sorare.com requires an operating licence or whether the services it provides do not constitute gambling.
Sorare.com is a fantasy football game based around blockchain, with users able trade player cards to build their own team. Players can also enter tournaments and compete for prizes worth thousands of pounds, based on the performances of players whose cards they own.
The site counts professional footballers Antoine Griezmann and Gerard Piqué, as well as former player André Schürrle, among its investors.
The Commission said it would not comment further on Sorare.com until it completes its ongoing enquiries.
In response to the warning, Sorare said in a statement that it was confident it did not represent any form of gambling that may require a licence, and that extra scrutiny was to be expected for a platform that had quickly grown in prominence.
“When a product with a nascent technology becomes successful, such as Sorare’s digital collectable cards and game, it is normal and expected for there to be regulatory questions,” Sorare said.
“We are very confident Sorare does not offer any forms of regulated gambling. This has been confirmed by expert legal opinions at every stage since the company was founded, including during a number of fundraising rounds.”
We will always engage and have an open dialogue with authorities who reach out to us to learn more about our game. We believe this is the responsible way to grow our game and community globally.”
The launch of Sorare.com in Britain comes after the collapse of Football Index, a site that was based around gambling in the future success of football players. Football Index was taken down in March following the collapse of its operator BetIndex.
Last month, an independent review from the UK government found that the Gambling Commission was too slow in its regulation of collapsed operator Football Index, and was unaware that operator offered a product it may not have been licensed to offer for more than three years.
The operator went into administration after mounting debts, the majority of which was money owed to players.
£4.5m was held in BetIndex’s player protection fund, which was used to cover the £3.5m worth of money judged to be held in player accounts when the business collapsed. However, the value of bets that were active at the time of collapse was a much larger figure, and the status of any possible reimbursement of these funds remains unclear.
Gambling Commission interim chief executive Andrew Rhodes then reminded players that the regulator would not pay back money lost by customers following the collapse of Football Index.