JOHNNY Mullins has left Oxford United after his loan was ended by Rotherham United.
The Millers are facing an injury crisis, so exercised the 24-hour recall option on the defender's deal with the U's.
It is a significant blow for United, with Mullins one of their most consistent performers since joining last month.
The 27-year-old made eight appearances, scoring twice.
U's boss Chris Wilder said: "Johnny has done well for us but we understand the situation at Rotherham with injuries and their decision to recall both of their loan players.
"These things happen in football and we move on."
Michael Raynes, Harry Worley and Andy Whing are in contention to fill the gap in central defence for United's home game against Northampton Town on Saturday.