Although he didn't make the trip to Bradford, he will be in the squad to face Fulham in the FA cup next week after another week's training following his loan move from Monaco.
He made his first appearance in a West Ham shirt against a strong Southampton reserve side last week, and says:
"I really enjoyed it and the team played well.
"We had a lot of chances to score but the Southampton goalkeeper was very good.
"The match was very quick, much more so than France where the pace is slower.
"But with match after match after match I will get used to it!
"And I know the first team is quicker still but I hope to play in the first team as soon as possible.
"Training is very strong - and all day.
"In France we relax the day before a match but here the day before training is tough."
Sebastien is settling in and adds:
"I know some of the names but not everyone yet - I am learning."