Southampton are believed to have beat two of their Premiership rivals to the striker's signature and will pay Oxford an undisclosed amount as compensation for the player.

"It's too good an opportunity to turn down really," Blackstock told the Oxford website.

"Southampton haven't got a huge squad, so I hope that if I can get a few goals in the youth side then I may get a chance in the reserves as well.

"Southampton have got players like James Beattie and Kevin Phillips up front so hopefully I can learn from them and continue to develop my game.

"I'm not expecting too much at first, but I am really looking forward to this opportunity and am determined to do well."

Blackstock has not played for Oxford's first team - but scored seven goals last week in two reserve and youth team matches.

Les Taylor, Oxford's Youth Development Officer told BBC Radio Oxford: "We're not going to stand in the way of the boy.

"He's been with us since he was nine. I do wish he could have played for our first team, though."