The Mirror claims that Villa have put a price tag on their 24-year-old captain that might be too much for United to consider.
They are able to ask for such a high amount because staying in the Premier League will give them a huge amount of television revenue, even if the coronavirus pandemic means that it is not clear when the club - or any other club in Britain - will be able to welcome fans back to their stadiums.
Grealish has three years remaining on his current contract, which means that Villa are in no danger of losing him for a free transfer any time soon, and so are in a comfortable position when it comes to negotiating a fee to sell him on.
The Mirror report that the player is on £65,000 a week, but signing for Manchester United could net him a weekly wage of around £200,000. If he were to stay at Villa he would hope to negotiate a contract that would earn him a similar amount.
Manchester City are also reportedly keen on the playmaker, and they will have to replace David Silva when he leaves the club at the end of their Champions League campaign, with Serie A team Lazio looking like his preferred destination.
United are currently in the running for Borussia Dortmund’s Jadon Sancho, with the 20-year-old England international subject of a tediously slow set of transfer negotiations that Ed Woodward specialises in. There is apparently a disagreement over the structure and size of a deal, with the German side wanting as much of the £100-120 million fee paid up front. As well as Grealish, United have been linked with Ousmane Dembele as a potential alternative to Sancho.