In this case, it's 30 year old South African Brett Evans, who has played for 13 years with South African league team Ajax Cape Town. (Why yes, the team is actually related to that Ajax.) He also has caps for the South African National Team, playing for Bafana Bafana in the 2008 African Cup of Nations.
According to his Wikipedia page, he plays left back rather than center back but I think we can all agree that all defensive depth is good defensive depth right now. Or who knows, he might be able to outplay Luis Zapata and Hunter Freeman for a starting spot if they bring him aboard.
Assuming that Jamie Smith gets his green card soon, the team will have one international spot open that could be used for a guy like Evans to come onto the team if they don't want to get Kohei Yamada back.