8:43 AM PT -- Errol's most recent opponent, Shawn Porter, is sending his love to Spence and his family -- telling TMZ Sports their professional rivalry comes second, Errol's health is the priority.
We spoke with Porter moments ago, who says he's been hearing POSITIVE things about Errol's health after the crash and is hopeful he'll recover.
In the meantime, he wants Errol to know he's rooting for the boxer and hopes he gets well soon.
We also spoke with boxing legend Roy Jones Jr.