After saying a transfer to the English Premier League was "possible", 26-year-old Griezmann was asked to rate the possibility out of 10.
"Six," he said without hesitation on French television channel TMC.
Atletico
are likely to be powerless over top-scorer Griezmann's ability to leave
with a number of clubs willing to meet his 100 million euro ($109
million) buyout clause.
Griezmann joined this season's losing Champions League semi-finalists Atletico in 2014 for 30million euros after five seasons at Real Sociedad.
Manchester
United are not for the moment guaranteed Champions League football next
season, Jose Mourinho's team aiming for victory over Ajax in
Wednesday's Europa League final for a spot after finishing sixth in the Premier League.