Don't. I have a 7'0 265lb PF LDD and he is still a PF/SF. I hate playing on the perimeter too.
If you are concerned about Pro Am, it will still mostly put you at PF, it'll put you at C and only seems to put me at SF if there's 2 bigger bigs.
If you are concerned about a long term My Career, before the first season is over I got the ability to change defensive matchups so that should help. I also got myself traded to the Cavs so that LeBron blocked the SF slot lol. Buf, I never play C on the Cavs even though they had only 1 or 2 C on roster. Tristan Thompson plays C over me and so does Kevin Love too.