Maybe it's being taken a bit literally. Perhaps, as a very rich fan, he'd like to own Marseille eventually. His mam, realising she wasn't popular, tells him that rather than starting there, he should run another club like us. If he does well, the fans there would be a lot more likely to accept him, if he still wants to do it. She can't guarantee he'd get the chance to run them, but with the money they've got I'm sure he could purchase them at some point
It's a similar meaning but means 'get his teeth into' rather than 'cut his teeth'.
I once tried a translation of 'by the skin of my teeth' here and everyone looked blank at me
