Leeds are facing a battle to hold on to Sinisterra, who is now training away from the squad as he seeks to push for a transfer this summer.
The Whites have already lost a plethora of players who had release clauses in their contracts that allowed them to leave on loan.
Leeds do not want to lose Sinisterra but the player is now applying pressure on the club to let him go.
According to Colombian broadcaster WinSportsTV, the winger wants Leeds to consider offers for him from a few of the interested clubs who want him.
Sinisterra does not want to play in the Championship when he has offers to leave Leeds for a better level of clubs.
Leeds want to hold on to him and are only prepared to let him go if his £22m release clause is triggered.
Talks are still ongoing between Leeds and his agents as all parties seek to find a resolution to the current impasse.
Losing Sinisterra would be a big blow for Leeds late in the summer window.