The 24-year old sevens specialist has been named on the bench for the pre-season game against Leicester Tigers at Welford Road, providing the Ospreys with another back row option.
Steve Tandy, Ospreys Head Coach, said: “We’ve been following Sam’s development for some time now, identifying him as someone with potential to do well at the XV-man game. After speaking to Wales sevens coach, Gareth Williams, we feel it’s the right time to bring him into our environment for the short to medium term, to help with his personal development and to see what he can do at this level.
“We are grateful to Gareth, and Geraint John, for their support and for facilitating this, giving Sam a great opportunity to shine.”
Cross was part of the GB sevens team at last year’s Olympics that claimed silver, losing to Fiji in the final after sweeping aside Japan, New Zealand and Kenya in the pool stage before defeating Argentina and South Africa in the knockouts.
A long-term stalwart of the Wales sevens team, Cross has played 170 matches on the World Rugby HSBC Sevens Series, scoring 51 tries. In the 16/17 series he scored 17 tries in 56 matches.
WRU head of performance Geraint John said: “Sam is a WRU contracted sevens player with a wealth of experience, representing his country in the World Sevens Series and of course starring for Team GB as they secured their silver medal in the 2016 Olympics in Rio.
“The Ospreys have given him a welcome opportunity to develop his experience of the fifteen-man game and it sounds like he has taken it with both hands already and impressed the coaches enough to have earned a place in a match day squad.
“He has played over a hundred games for his country on the sevens circuit and is still very much an integral part of our sevens plans, but this is a fantastic opportunity for him in terms of his personal development and who knows where it may lead.
“This move is also a great example of the close working relationship established between Gareth Williams, the Wales Sevens head coach, and the coaching staff at the regions. In this case Gareth has been closely aligned to Steve Tandy in terms of looking after the best interests of the player and his future development.“
