The invention refers to a sequential combustor arrangement having a first burner, a first combustion chamber, a mixer for admixing a dilution gas to the hot gases leaving the first combustion chamber during operation, a second burner, and a second combustion chamber arranged sequentially in a fluid flow connection. The mixer includes of injection tubes pointing inwards from the side walls of the mixer for admixing the dilution gas to cool the hot flue gases leaving the first combustion chamber. A flow guide is arranged in the connecting duct and/or the injection tubes for guiding the dilution gas into the injection tubes. The invention further refers to a gas turbine and a method for operating a gas turbine with such a sequential combustor arrangement.