Dundee United boss Peter Houston has confirmed Francisco Sandaza, Danny Cadamarteri and Jennison Myrie-Williams can leave.
Houston is keen to bolster his central defensive options after Andy Webster's return to Rangers and Lee Wilkie's retirement.
United's boss has a plethora of strikers and feels he will need to trim his numbers up front in order to free up some funds to strengthen his backline.
Houston has confirmed Sandaza is training with Championship side Swansea in a bid to win a deal, while the futures of Cadamarteri and Myrie-Williams are now uncertain.
Free to go
"I spoke to the three players and told them if someone comes in for them we wouldn't be difficult to deal with," Houston told the Daily Record.
"Fran is at Swansea for a few days to let them have a look at him. He's a quality player but has had fitness problems.
"We've brought players in and renewed contracts which is all money spent without bringing any in.
"We thought someone would have been sold by now but it hasn't happened so I have to free up cash.
"I need a centre-half and it looks as if a striker will have to make way to get the man we want in. If nothing comes of the Swansea trip, Fran will come back."