Protect back of seat from kids shoes?

My 18m old swings his feet into the back of the car seat and is catching the seat pocket (sportline). If I don’t find a way to protect it soon, it’s going to be trashed.

Does anybody know a seat cover that just covers the back of a sport line seat?

Even if it was some sort of object arranger/pocket that they can put things in. Just something to stop his heel digging in to the pocket and pulling at it…

thanks