This has happened since day 1 in the game and I’ve just deleted my PCM save yet again. I was number 7 with a club, transferred and it gave me 14. Checked the available numbers and 11 was free. Next game I played it gave me 7 again, and the team had 2 number 7’s on the pitch. EA don’t care about career mode, especially not player career, so I can’t see this being fixed.