The 19-year-old has linked up with the U's after on-loan Conor Ripley returned to parent club Middlesbrough and both first and second choice keepers, Ryan Clarke and Wayne Brown, were ruled out through injury.
With Arsenal's reserve team campaign now complete, Oxford manager Chris Wilder has drafted in the Argentina youth international after a string of impressive performances ahead of the game at Vale Park.
Oxford must beat Port Vale and hope that Crewe lose at home to Aldershot if they are to grab the final play-off spot at the Railwaymen's expense.
"We have worked very hard to get a quality keeper in," Wilder told the club's official website. "Initially we were looking for someone with experience but it is a very tough time of year.
"Damian came with tremendous recommendations and we saw him play well on Wednesday night for Arsenal reserves, so we had no hesitation in bringing him into the squad."