Sullivan, 23, will get a rare run out for League One leaders Charlton when they travel to Fulham today.
He said: "I was in the Brighton youth team when Bobby was banging in the goals for them.
"I don't know him, I was only 15 at the time and he was the club's star striker.
"But I am a massive Brighton fan and I used to watch him every week and sing his name. He was one of my heroes so to play against him will just be amazing.
"I just hope I do myself justice and put in a good performance."