The Frenchman has only played seven times in the Premier League this season, scoring just once, and now he is looking to move on from the club.
"I think if they can get good money for him," Neville told Sky Sports News.
"I think that now the time has come. I think Manchester United have always been wary of getting burned, of him leaving for £25m and then going on to become a £100m player because he is a special talent.
"I just don't think he'll ever work at Old Trafford to the extent they've got [Marcus] Rashford, [Mason] Greenwood, [Cristiano] Ronaldo, [Edinson] Cavani, other players as well."
Manchester United will play Brentford on Tuesday night, but Martial is yet to feature under Ralf Rangnick. body check tags ::