Reading defender Ibrahima Sonko will have an exploratory knee operation on Tuesday after sustaining injury against Sheffield United.
Sonko was replaced by Andre Bikey two minutes before half-time after turning awkwardly and a scan showed surgery was required.
Team-mate Dave Kitson will also have a scan.
Kitson, who was hoping to make his Premiership comeback after being out with knee trouble since the opening game of the season, strained a thigh muscle in the warm-up prior to the Blades clash and had to be replaced on the substitutes' bench.
Physio Jon Fearn told the club's official website: 'We don't think Kits has done anything major, but we'll have get a scan done on Tuesday just to be certain.'