Trials for a reverse shoulder system are described. The trials generally include an insert housed within a humeral cup. The insert has a proximal end and a distal end, the proximal end having a concave recess therein adapted to receive a glenosphere prosthesis. The distal end of the insert includes a shaft, the shaft is substantially housed within the confines of the humeral cup. A distal end of the humeral cup is inserted in a humeral stem.