Simian became a professional tennis player in 1991 and was already in his first individual final on the ATP World Tour the following year . In Tel Aviv, however, he was defeated by Jeff Tarango in three sets . He had his greatest successes in 1994, when he was able to win the tournament in Doha and Seoul and was in the finals of Delray Beach with Ken Flach . He reached his second and last individual final in 1996 in Rosmalen ; there he was defeated by Richey Reneberg in two sentences.
He won five doubles and two singles titles on the ATP Challenger Tour . He reached his highest scores in the ATP world rankings in 1993 with position 41 in singles and in 1994 with position 56 in doubles.
His best individual result in a Grand Slam tournament was reaching the third round of the Australian Open and the French Open . In the doubles competition in 1994 he stood alongside Jean-Philippe Fleurian in the round of 16 of the French Open.