Being able to interact with the manager and have some semblance of control over your career has been a wish list item for many years now. At one point, SDS implemented some things. You could talk to your manager every so often (like every 60 days or so) and do things like ask for more playing time, ask for a position change, ask to be traded. I think this was back in 2015 or so - maybe earlier. Obviously that's gone away and it's been replaced theoretically by your agent interactions. Which to the point of the OP, I do not believe allow you to change your fielding position. Which is dumb. Think of when the Yankees signed A-Rod as a FA while already having Jeter at SS.
Converting to Archetypes was a great opportunity for SDS to improve this aspect of the game (secondary positions and roster flexibility). They could have put in code that lets everyone play at whatever position the Archetype supports without a "out of position" penalty. This would have allowed a lot more flexibility in lineups and potentially provided more opportunities for the player to get into the game. But it appears SDS made an error on the play, so to speak...