Defenders Martin Cranie and Tom Kennedy have not travelled with the Barnsley squad for the pre-season trip to Italy and could be on their way out of Oakwell.
Left-back Kennedy, 29, and centre-back Cranie, 27, have been training with the youth team this week and could be part of an exodus as the Reds look to trim their squad down following relegation to League One.
Barnsley are in talks with Championship club Blackpool over the sale of captain Cranie. He has won Player of the Year awards for each of his two seasons at Oakwell but has been relegated from the Championship three times in six years.
Blackpool currently have just eight senior players, including ex-Red David Perkins, but are thought to have enough money to secure Cranie. Any movement in unlikely before the settling of a dispute between Pool chairman Karl Oyston and manager Jose Riga, who allegedly wants to bring in four foreign players before signing anyone domestically, which could result in Riga leaving before his first game.
Last season's top-scorer and Player of the Year Chris O'Grady travelled with the Barnsley squad to Italy but is now understood to be close for signing with Brighton.
Barnsley are desperate to offload some of their highest-paid players and avoid a transfer embargo under League One's salary cap rules. They have always expected interest in Cranie, O'Grady, Dale Jennings and Luke Steele, who left this week, but wanted any business to be done earlier in the summer so they could begin to bring in new players before the season starts on August 9.
So far they have recruited striker Kane Hemmings, midfielder Conor Hourihane and untested goalkeeper Adam Davies who have all gone to Italy along with senior players Jean Yves M'voto, Lewin Nyatanga, O'Grady and Jennings.
Ten of the players who travelled to Italy with the Reds are teenagers while ten have also never played a competitive match.
Following the departures of Steele as well as Bobby Hassell and Jim O'Brien earlier in the summer, Barnsley's longest-serving player is now Reuben Noble-Lazarus. The winger, who does not turn 21 until next month, made his debut in 2008 and has played 47 first team games.