The 24-year-old has been in impressive form for Villa during the 2019-20 campaign, scoring nine times and contributing eight assists in 35 appearances in all competitions.
"It's our understanding that Borussia Dortmund have entered into the race for the Aston Villa captain, who has been linked to Manchester United and other clubs in the Premier League," McGarry told the Transfer Window Podcast.
"A move to Dortmund would certainly be a departure for a young man who has grown up at Aston Villa, and has expressed his preference for a move in England. The problem is the fee.
"However, it's also the case that United are waiting to see Aston Villa's fate in terms of relegation from the Premier League. They have the belief that if they do go down, both the player and the club will be much more open to the move."