A combustor includes a plurality of tubes arranged in a tube bundle and supported by at least one plate that extends radially within the combustor, wherein each tube includes an upstream end axially separated from a downstream end and provides fluid communication through the tube bundle. A flow conditioner extends upstream from the upstream end of one or more of the plurality of tubes, and a radial passage extends through the flow conditioner. A method for distributing fuel in a combustor including flowing a working fluid through a flow conditioner that extends from a tube that is configured in a tube bundle comprising a plurality of tubes and that is supported by at least one plate. The flow conditioner includes at least one radial passage to impart radial swirl to the working fluid. Flowing a fuel through an annular insert that is at least partially surrounded by the flow conditioner.