If by play you mean run, then by all means, yes.
If you, however, mean that they're actually playable, then no.
MAYBE, but just maybe, minimum settings at minimum resolution will keep you above 30 fps, but anything above it will likely stutter badly.
I can understand you don't want to change your video card, so I'm pretty sorry, but there really is no other way to improve the situation. To be honest, you need more than a GPU upgrade there....