The Rangers star has been linked with A-League clubs Queensland Roar, North Queensland Fury and Perth Glory but McDonald believes the 31-year old still has quality to offer the Scottish Premier League.
“I wouldn’t necessarily think that would be the right move for him yet,” McDonald told the Scottish Sun.
“I think he’s a little bit too young for that even if that might sound a little bit disrespectful to my own country.
“It would be a really big coup for Australian football and a fantastic thing for our country.
“But I think Barry would be best served in Europe. He still has a lot to offer at the highest level.”