An arrangement for a turbomachine combustion chamber is disclosed. The arrangement includes 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 an annulus, an injector system associated with the opening and including an annular bowl that is flared downstream, passing through the opening, and a pinch ring that cooperates with the annulus to allow the injector system to shift off-center relative to the chamber end wall. The deflector includes an annular collar extending radially inwards. The bowl of the injector system includes 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 when the injector system shifts off-center relative to the chamber end wall.