Milne played the opening 32 minutes for United's reserves in their 3-2 loss at Grimsby Town on Wednesday night.
"He did very well and it's all part of his rehabilitation, we're pleased with him," Crosby told the club's official website.
Milne has not played for 13 months and has has two operations. Andrew Wright played the full game as he closes in on a return from a broken bone in a foot.
There was one injury blow, however, for the Iron as Ben May had to be replaced after 16 minutes because he suffered an ankle injury.
Garry Thompson scored twice for the Iron, but a brace from the Cod striker Peter Bore and the home trialist Chris Ramsey secured some local pride for the League Two strugglers at Blundell Park.