Oxford United midfielder Simon Clist will miss the opening stages of pre-season training after undergoing a hernia operation.
Chris Wilder's squad returned for some pre-season tests on Thursday and the Oxford boss confirmed Clist had been in for surgery.
The 29-year-old played a major part in helping Oxford gain promotion back to the Football League last season and Wilder expects Clist to soon be back in his plans.
"Clisty will miss the first week or two of training because of a hernia op, but he is a naturally fit lad and will work with the physio and we expect him back quite quickly from that," said Wilder.
Meanwhile, the Oxford boss believes he is close to finalising his squad for the League Two campaign after bringing in eight new signings to date.
He told the Oxford Mail: "We'll probably run with 20 or 21. If something comes up, we might go for it, but on the financial aspect of it, we'll not put anything in jeopardy.
"We've done things sensibly, as we have done the last 18 months.
"We feel we're signing players at the right age too, that are going to be assets to us. And if they do well with us, and move us forward, great - and if they do well there's no doubt that they will attract interest."