Robinson, 33, is set for a lengthy spell on the sidelines after suffering serious respiratory complications following a back operation last week.
The former England international developed a pulmonary embolism (blood clot in the lung), which will rule him out for the next six months.
Robinson has returned home to recover after being held in hospital over the bank holiday weekend.
Meanwhile, fellow keeper Kean sustained torn cartilage in his left knee in Easter Monday's 3-0 defeat to leaders Cardiff and will undergo an operation to rectify the problem.
The 22-year-old is expected to be out of action for up to six weeks, but should make a full recovery in time for the start of next season.