Reading midfielder Brynjar Gunnarsson requires a groin operation that will keep him sidelined for another four weeks.
The 32-year-old Iceland international has not played since the 3-1 defeat at Aston Villa in January because of the problem, but returned to training last week.
However, the injury has not completely cleared up, with physio Jon Fearn telling the Royals' official website: "Brynjar's off to London to undergo a procedure.
"He was progressing well and trained late last week, but he was still having discomfort.
"So, rather than wait until the end of the season, we decided to deal with it now and get him pain free and 100 per cent as soon as possible."
Meanwhile, Steve Coppell has taken his players to Spain for a training camp, with Fearn adding: "We're in a very nice environment, set in the hills off the Spanish coast.
"Glen Little got involved in light training, so that's promising for him."
