The Gloucester-born wing made his Arms Park debut in 2011 but his future has been up in the air since it emerged the region had shown an interest in signing George North from Northampton.
Although the speculation has since been quashed due to a need for front-row signings, the emergence of wing Owen Lane and full-back Rhun Williams means Cuthbert is expected to leave in the summer.
The 27-year-old has scored 16 tries for Wales, including the Grand Slam winning score in 2012, while he also touched down for the British & Irish Lions in their first Test win over Australia in 2013.
However, he has struggled with fitness in recent years and has only just returned to the Blues side after a calf injury.
Although his exit is yet to be confirmed, Cuthbert is expected to move to either France or England, a decision that would more than likely end his international career.
The WRU's selection policy is to only pick overseas-based players with 60 caps or more and the wing's current tally of 47 would render him ineligible should he move abroad.