Common Ringtail Possum

From what I could see I didn't see any bleeding wounds, only the scratch mark on its tail which have looked like it already healed and that small dark patch on the on its back. I thought It could've been an old or sick possum?

I'm not to sure if it was injured, that was my first thought. However it began to eat the flower buds I collected and move into the shrubbery where I places them. I was observing it for 30mins and was very inactive. It closed its eyes every now and then as if it was drifting in and out of sleep.