There are a few ways to find him. Flopperboy pointed out one-under WGT Community tab above just enter their name. If that doesn't get results-and sometimes it won't if they're sitting in time out-try to find a post that person made as the link to his profile is active. You can also try searching his name over there>>>>>, you might get lucky.
Also, if you ever played an AS game with him as a partner and won, you can find that game in your activity on your profile. The links in green are all active. Even if, for whatever reason, he deleted you and blocked you you can still locate him, you just won't be able to post on his wall. If you ever PM'd him and didn't delete the convo, you can find that in your PM history and still be able to PM him.