RC Lens became Muslin's home in the summer of 1996.

He then joined RC Lens, and eventually became club captain during his three-year stay.

He left the club at the end of the season and rejoined RC Lens.

In 2003, he moved up north to the next region over joining RC Lens on a youth contract.

He joined RC Lens in the summer of 2004.

He was fired by RC Lens for doping in 1996.

He played most of his career in France, with RC Lens.

He has also managed RC Lens on four different occasions.

He began his football career in the youth system of RC Lens.

Further to this they received a €130,000 fine, payable to RC Lens.