Barnsley are struggling to retain the services of highly-rated defender Andy Yiadom.
Sky Sports sources report that the player, with one year left on his contract, has rejected a new offer from the Oakwell Club as newly-promoted Premiership neighbours Huddersfield Town close in on his signature.
The Terriers, who have had offers of £1 and £1.5 million turned down, are expected to come in with an improved bid.
It will be a blow to the Reds if the 25-year-old Ghanaian international does leave because he had an outstanding season last term, when he forced his way into the first team and went on to make 32 SkyBet Championship appearances.
Barnsley snapped him up on a free transfer from League Two side Barnet in May last year. Before that he had played only non-league football with Hayes and Yeading and Braintree.
Swansea are one of a number of other clubs who have shown an interest during the summer.