TORONTO -- Juno-nominated crooner Robin Thicke has postponed a concert at Ontario's Casino Rama due to an "unexpected vocal issue."

The 37-year-old has moved the Rama show to July 26, with tickets to Tuesday's original show still to be honoured.

Refunds at the original point of purchase are also available.

Thicke has cancelled several concerts recently amid reports of his separation from wife Paula Patton.

The "Blurred Lines" singer, who's the son of Canadian TV star Alan Thicke, has publicly campaigned during live performances for Patton to take him back.

He still has American tour dates throughout the month, leading up to a scheduled performance at the Juno Awards in Winnipeg on March 30.