There is no way to repair it, you can try putting it back with some T.T. glue but I doubt that it will stick. If it is torn at the edge then it should not affect your strokes and general play. Otherwise, just get a new sheet.
Can you show a photo. It is hard to help without seeing the specific issue.
I have had tears and rips to the top sheet or sponge where glue worked fine to keep that area from getting worse. But I have also had tears where glue was not going to help.
But water based glues are really good for bonding sponge to sponge and rubber to rubber. They hold really strongly when it is rubber to rubber. Much stronger than how they hold wood to sponge.