Mason, who has played rugby league for Australia, made six appearances for Hull KR before his failure to obtain a Tongan passport led to him being de-registered and then joining wealthy French club Toulon.
Despite not having played in the 15-man code Mason revealed he had been selected to face England at Twickenham and then Wales in Cardiff six days later.
He said: "I am just so excited to be playing rugby and I'm looking forward to the
challenge,.
"I've certainly jumped in the deep end in agreeing to play for the Barbarians without having any rugby experience.
"If you ask all the boys, I've always told them I've wanted to have a crack at rugby (union), and I'm ready to try the best I can to make an instant switch."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.
