Redoing a Card

Hey ya'll, apologies if I sound like a nub , but I've never been aware that when a player gets an upgraded rating & you still have the previous version it doesn't max it to the updated rating

Let's take the example above , I am aware Clauss has an 80 rated version would I need to sell this one & pray it comes back to the shop / is there a different method people use to redo cards

Please assist, 8/11 of my starting XI are on older ratings & I'd need to know what to do going forward