Michael Laudrup has blocked Neil Taylor's move to Fulham because the defender is needed at Swansea as cover.
The Cottagers saw a bid in the region of £4million rejected last night, but could return with an improved offer before the window closes.
However, Swans boss Laudrup admits he can't let Taylor leave as he has no one else to fill in for first-choice left-back Ben Davies.
“I understand Neil’s frustration,” he told the South Wales Evening Post.
“I have had a talk with Neil. It is a situation where someone has taken his place after injury. I understand his position and I always think we should be here to help people.
“But players are part of a group and it is not about the interests of Neil Taylor or Michael Laudrup but the interests of Swansea City, and right now – because of the number of games we have plus the injury situation in a small group – it means if Neil goes we need another one.
“If we let him go and something happens to Ben [Davies] then everyone would kill me - the only one satisfied would be Neil.
“But I do understand his position because he wants to play and recover his position in the national team too.
“If we get another player in then perhaps my view would be different, but it would be very difficult to do that at this stage of the transfer window.”