A combustor includes an end cap having an upstream surface axially separated from a downstream surface and a cap shield circumferentially surrounding the upstream and downstream surfaces. A first circuit of tubes extends from the upstream surface through the downstream surface. A first fuel plenum is in fluid communication with the first circuit of tubes. A second circuit of tubes extends from the upstream surface through the downstream surface. A second fuel plenum downstream from the first fuel plenum is in fluid communication with the second circuit of tubes. A method for supplying fuel to a combustor includes flowing a working fluid through tubes, flowing fuel or diluent from a first fuel plenum through a first circuit of tubes, and flowing fuel or diluent from a second fuel plenum through a second circuit of tubes, wherein the second fuel plenum is downstream from the first fuel plenum.