I'm not telling you to play matchmaker, but if there's an opportunity to let them "naturally" meet - I'd do it. Like, schedule his appointment for noon (with someone else), tell your friend to come get lunch with you and pick you up at 1130am at your office, and oh, they both just happen to be there in the waiting room. Introduce, then tell friend something just came in that you have to take care of, please hold on a minute, and go be "busy" with something and then hope that they chat. That's the extent of what I'd do...