Change defensive assignment in my player mode?

Is it possible to change defensive assignment in my player mode?
I'm a 6'3 PG and my club often plays me at SG (sometimes even at SF) where I've been matched up against guys 6'6-6'9 and they just easily beat me in the post shoot over me or just walk under the basket and make the easy layup and most of the time I can't do anything about it...

You think that's difficult? I play as 6'3 SG with no athletic abilities and half of the time I've to guard players like Al Jefferson, KG, LeBron, Melo etc.
I don't know why but Hawks constantly sub me in as PF (I'm their starting SG).

I've been subbed in at PF, but the next dead ball, they put me back at SG. So, call for the ball, and call timeout, or lose some grading and intentionally foul. I don't think anything bad can happen from calling timeout.

yeah that's very annoying I'm 6'6 SG but they put me on SF and it's a little bit hard for me to guard players bigger than me in the post

Im a 6'8 SF and i dont mind playing SG or PF but it would suck to be a g and have to be a small G and have to guard a F

I've been subbed in at PF, but the next dead ball, they put me back at SG. So, call for the ball, and call timeout, or lose some grading and intentionally foul. I don't think anything bad can happen from calling timeout.

Thanks, but unfortunately it didn't work... I'm the starting PG of Blazers and around halfway through the 1st quarter they switch Roy to PG and me to SG and I pretty much play there the rest of the game...

you think thats hard? my player is a 6'9 power forward and the coach subs me in at sg, and i had to defend dwyane wade for the whole game, he effin burned me for 22 points. on 5 min quarters.

yeah they switch me to SF but im PG 6'3 im guarding 6'6 to 6'8 ... though i can block then, i can bother them with sneaky steal anyway it doesnt work most of the time i get shoot over...

another thing --- i hate the help defense T_T i wish i could turn it off... instead of being scored by 2 pts they get 3 pts damn... it hurts... i wish there is no help defense... i wish i could tell my team mate not to help defense at least...