As reported by Goal, Championship outfit Blackpool accepted an £8 million bid for the 21-year-old two weeks ago, but the deal has so far failed to materialise, with the two parties thought to be discussing personal terms.
|11/8||Cardiff are 11/8 with William Hill to be relegated
"There is no ultimatum of any kind," Mackay told reporters. "This was always the timescale.
"Tom and his father have been on holidays and they also had some domestic issues to sort. Now they have had time to think and the ball is in their court.
"We will have Tom's decision on Friday morning. If he wants to become a Cardiff City player then great, but if not we will move on to out next targets."
Whether the young winger will choose to make the switch to the Premier League remains to be seen with his father, and Blackpool manager, Paul insisting that the deal may still not happen.
"Thomas knows he will play in the Premier League one day but there is no rush," he told the Blackpool Gazette. "He has said he is happy at Blackpool and really enjoys his football."