Legal aspects surroundings Scotland's bid to host games at Euro 2020 "may have to be re-assessed" if the country becomes independent following next week's referendum, according to Uefa's report into bidding countries.
The Scottish FA has submitted a bid for Glasgow's Hampden Park to host three group games and one match in the knock-out rounds of the tournament, which is being held in 13 countries around Europe.
Cardiff's Millennium Stadium and the Dublin Arena are also bidding for group matches, while Wembley is the favourite to host the final with only one rival in Munich.
UEFA's executive committee will vote on the host cities on September 19, the day after the Scottish referendum.
The evaluation report carried out by UEFA into the bids says of the Scottish bid: "Scotland being part of the UK, the legal situation is mostly - but not entirely - identical to that of England and Wales.
"The situation may have to be re-assessed should Scotland become independent of the UK following the referendum."
The evaluation report also criticises the commercial part of the Scotland bid as being "inadequate" and "lacking clarity".
It says: "The commercial sector of the bid is inadequate, as the information provided lacks clarity. The amount of advertising space offered is vague."
Glasgow's transport links and hotel accommodation are praised however, as is its plans for fan zones.
Cardiff's bid gets a generally favourable evaluation report, but inspectors point out that fans would have to use airports in Bristol or even London.
Dublin receives one of the best evaluation reports among all 19 bidders, with hotel accommodation praised as "very impressive".
The evaluation report of the FA's Wembley Stadium bid is generally positive and similar to that received by Munich, although the proposed fan zone outside of central London is rated as only "satisfactory" and plans for fan zones in other English cities as "very weak".
Munich's fan zone proposal is rated as "attractive" but plans for fan zones in other German cities also rated as "weak".
Wembley is regarded as the favourite after the German FA announced it may not push hard for Munich in order to concentrate on a bid to host the entire Euro 2024 tournament.
UEFA's report also raises concerns about the political situation in Israel and Russia, who are also bidding with Jerusalem and St Petersburg respectively.
The political situation in Israel is described as "complex" due to the recent Gaza conflict and Russia's as "increasingly complex", following its involvement in the Ukraine crisis.