I had a similiar problem this spring. If you end up with a lot of water behind the liner don't forget you can use the pool pump to vac out the water much faster than a small pool cover pump. Also if you have trouble getting the liner back in bacause it has shrunk. Use either a hair dryer to heat up the liner and buy yourself some stretch or I used a paint remover heat gun from Home Depot. Becareful with the heat gun it will produce enough heat to damage the liner. I had some major shrinkage so I needed a bit more ooompf than a hair dryer could provide. Worked great.

Chuck