In the near future, the PHENIX experiment at Brookhaven National Laboratory will install several upgrades to enable an extended physics program in the next decade. Centerpieces of this effort will be new vertex detectors, forward calorimetry and a muon trigger upgrade. This work will focus on the latter two. The planned forward calorimeter, FoCal, will bridge the gap in the acceptance between the currently installed electromagnetic calorimeters in PHENIX in the pseudorapidity range 1 to 3. Using silicon tungsten technology, it will enable the measurement of direct photons and neutral mesons as well as jets in a kinematic domain that will allow access to low x values in heavy ion and polarized proton collisions. This is especially true in √ s = 500 GeV proton-proton collisions. At these energies, a milestone in the RHIC spin program is the measurement of the sea quark polarization of protons via W production. Using the parity violating nature of the weak interaction, single spin asymmetries can be used to access this quantity at high momentum transfers and independent of quark fragmentation models. In order to detect muons from W decays, an upgrade of the PHENIX muon trigger is currently underway. It consists of new detector stations using RPC technology and new FEE for the existing muon tracker stations.