There is still a difference between him knowing Jamal and him remembering Jamal. Is Jamal present when this question is asked? Is it part of an introduction?
I would probably say something like "Do you remember meeting someone called Jamal when a big group of us played basketball a few days/weeks/months ago?" I agree with Matthew Wai that if the person might have met Jamal but not realised it, you'll probably have to show him a photo of Jamal or at least try to describe him.
I have no idea what you thought was funny about my suggestion. I was being perfectly serious.
"We all played basketball together last time" is grammatically correct but suggests that you are absolutely certain that you, the listener and Jamal played basketball together on the last occasion you played basketball.