It appears German coach Ernst Middendorp has used his influence in trying to get Bangkok to lure Castro.
Middendorp – who has vast PSL coaching experience – is currently the technical director at the Thailand club who are evidently in need of a striker with plenty of their goals this past season having come from midfield.
What remains to be seen is how far Bangkok can stretch their budget to take Castro away from Chloorkop before the close of the Thai transfer window in February.
Sundowns are said to be open to releasing Castro in January but will only take an offer from the highest bidder.
Castro’s contract with the club runs up in June, which essentially means if The Brazilians don’t cash up during the next transfer window then they run the risk of seeing the Colombian walking away on a free.
What Sundowns know for sure is that the 28-year-old will not be renewing, with the Colombian having long made the club aware of that decision.
Word reaching this website is that Kaizer Chiefs also did put in a hesitant word of interest to test the waters but appear not keen to pursue while he is still under contract at Sundowns.
Chiefs are not interested in paying a transfer fee and will only want to bring him on board as a free agent – which means waiting until the end of June.
Castro was the last foreign player registered by Sundowns after the club failed in its bid to land Jeremy Brockie from SuperSport United.
He missed most of the pre-season as he awaited the birth of his son back home.
The PSL now allows clubs to make substitutions – during the January transfer window – on the five players that they will have registered as foreigners at the beginning of the season.
Previously, no changes could be made on the five foreigners that clubs will have registered for the season regardless of what happens during the season.
The Brazilians are aiming on using that rule to make changes in January should they not get the kind of value that they are aiming for from Castro – who is going to be out of contract next June.
As is known Castro can already sign a pre-contract with a club of his choice in January when he enters the last six months of his contract.
The five players registered as foreigners by Sundowns this season are Castro, Fares Hachi (Algeria), Ghana keeper Brimah Razak and the Ivorian pair of Bangaly Soumaharo and Yannick Zakri.
Brazilian defender Ricardo Nascimento remains under contract and is working his way back to fitness at Chloorkop after failing to reach a termination agreement.
However, coach Pitso Mosimane recently suggested Nascimento is free to join any team.