The current railway infrastructure at Sandhills will not be able to cope with the demand from a crowd of over 50,000 people, nearly all of whom will leave the stadium at the same time, many expecting to use the railway. There are not enough 777s to make all trains 8-car and Sandhills station was never designed to cope with crowds of any size. Even if the size of the fleet was to be increased, the station would require massive investment to provide loops and 4 platforms. Older readers may remember that Sandhills once had 4 rather narrow platforms but today’s safety requirements would mean widening the site to accomplish this. Very expensive and most unlikely to happen.
What is required is a network of bus services on matchdays, covering locations on a 5-10 mile radius of the ground, plus the Wirral, leaving the railway to cater for those from further afield and the not match-going passengers.