If i'm Warne, I would be telling Adams to prove he wants to be here next season by putting in a transfer request and to push the issue with his parent club.
Cardiff don't have much leverage in this. From all indications, they clearly don't rate him. If we don't meet Cardiffs asking price, are they prepared to let him rot in the reserves whilst wasting their wage budget on him? Espically with regards to FFP, where his wages can be put towards a player that can contribute more for Cardiff, it would be cutting off their nose to spite their face.
I would imagine the 300k we've offered are subject to appearances or success, and structured like the Washington deal last summer.