Hello,
If the pot is damaged then it should be replaced. When you knock the plant out of its pot check to see if the plant is rootbound, for instance are there roots coming through the base of the pot? Repot the plant into a new pot one or two sizes larger, gently remove as much of the old compost as possible and replace with fresh, water thoroughly and allow to drain well. After a couple of weeks start to feed with a high potash low nitrogen fertilser. I find that tomato fertilser is ideal.

Thanx