Oxford have signed Australian winger Ryan Williams on loan from Fulham until January.
The 19-year-old, brother of Middlesbrough's Rhys, came through the Portsmouth academy and made six appearances before moving to Craven Cottage in January 2012.
Williams finished last season on loan with Gillingham before representing his country at the Under-20 World Cup in Turkey.
"He's a good player and will give us competition in an important area," manager Chris Wilder told the club's official website.
"He has a good pedigree, has pace, and is very highly thought of at Fulham, a club we have an excellent relationship with."