The man who played Gary Coleman's sitcom father on "Diff'rent Strokes" tells TMZ he's aware of Gary's tragic situation -- and says he's "hoping and praying for his recovery."

Conrad Bain, 87, -- who played Philip Drummond on the show -- tells us the two haven't spoken in years ... but with the recent reports, Gary is definitely in his thoughts.

As we previously reported, Coleman is currently on life support after suffering a intracranial hemorrhage earlier this week.