Keane had to be withdrawn from the FA Cup win over Shrewsbury last month just four minutes after coming on as a substitute.
It was a huge disappointment for the 23-year-old, who was hoping to make an impact at Old Trafford following a loan spell at Preston North End. Van Gaal revealed that Keane’s surgery was similar to the one that Ashley Young went through in January.
“He is coming back [to England] on Tuesday, and I’m hoping he comes back [to play] as quickly as Ashley Young.”
Keane has had terrible luck with injuries over the course of his career.
The forward had enjoyed a sparkling goal record at youth level but he sustained knee ligament damage in 2012 which kept him out for a number of months. The latest setback will come as a blow but there is no reason why he can’t come back stronger next term.