He reckons that the Hammers should look abroad to Rolland Courbis, the former Marseille boss in his late 40s, and says:
"If you talk to players that know him, such as Titi Camara who played under him, they will tell you that he has a lot of charisma and can motivate players.
"He has had a lot of success in France and I think, with his methods and mentality, he could push West Ham to new heights."
Sebastien insists that Harry Redknapp would have kept him on had he stayed at the club, and says:
"Harry promised that I would stay here next season, and he had spoken to the Metz president.
"He wanted me next year, but now he has gone that has changed.
"I have to thank Harry because he got me out of a bad situation in France where I had a bad reputation, and he made me well known over here in the best championship in the world.
"I know other clubs are interested in me but my priority is to stay with West Ham.
"But I will be speaking to other managers, and if I am not wanted here I will go elsewhere in England.
"But I really want to stay at West Ham - my family adores the club, which is friendly and has a great new stand going up.
"I'm not looking for anything else, and I don't want to be treated like a star."
Ironically, one of the clubs chasing Sebastien also has its own managerial issues - Saturday's opponents Middlesbrough.
He says that the game against them must be treated like any other, insisting:
"We are there to defend the colours of West Ham whether it is with Harry as boss or anyone else.
"I am happy for Glenn to be taking us, he talks to us a lot, and he will have us motivated for Saturday.
"Like any other coach he only has one thing in his head, which is to win the game - and he will have us ready for that challenge."
Sebastien was indeed recommended to Harry by Glenn Roeder who described him as one of the best attacking full backs he had seen.
He first came to the club's attention after the Hammers played Metz in the InterToto cup, and Glenn kept tabs on him thereafter.
But he admits that he was shocked by the decision of Harry to quit, and says:
"It was a bizarre decision, and I just can't understand it, especially as we had just saved ourselves.
"But we are here to play whether it is Harry, Pierre, Paul or Jacques as boss!"