Former Blues prop Pauliasi Manu faces an uncertain future in the sport after failing a medical at the Melbourne Rebels.

Manu was snapped up by the Rebels after being delisted by Blues coach John Kirwan, a strategic decision which backfired, but now the 24-year-old has returned to Auckland.

The Rebels released a statement today saying Manu had returned home after a pre-employment examination revealed an unspecified medical condition that required further investigation.

"I'm gutted I'm not going to play for the Rebels next year, especially after coming over the first time and meeting the team and management. The environment was positive and their aspirations were high and I was hoping to be part of the journey next year. We'll see what happens in 2014,'' said Manu, who signed a two-year contract with the Rebels last month.