The invention relates to an arrangement for a turbomachine combustion chamber, comprising a chamber end wall pierced by at least one substantially circular opening, a deflector mounted from the downstream side of the chamber end wall in the opening by means of an annulus, an injector system associated with the opening and including an annular bowl that is flared downstream, passing through said opening, and means enabling the injector system to shift off-center relative to the chamber end wall, the deflector including an annular collar extending radially inwards, and the bowl of the injector system including at its downstream end an outwardly-open annular groove radially in alignment with the collar of the deflector in such a manner as to enable it to retract into said groove in the event of the injector system shifting off-center relative to the chamber end wall.