Strangely the source in question has suggested it's likely to be a Filipino which is very hard to believe given that the only WBA top 15 ranked Filipino is Arthur Villanueva (26-0, 14). Villanueva is ranked by all 4 bodies, including a #7 ranking by the WBA, and is unlikely to risk his rankings in a bout on the road against Tso. We'd suspect however that Tso would be more likely to battle one of the two ranked Thai's, either #3 Norasingh Kokietgym (13-0-1, 10) or #9 ranked Petchbarngborn Kokietgym (30-7-1, 13), both of whom are more likely to travel to Macau for a bout with Tso. As we know however fights can effectively be ranked at a whim and seeing a new Filipino being ranked between now and March wouldn't be a huge surprise.
According to the source the winner of Tso Vs "TBA" would become the new mandatory challenger for world champion Kohei Kono (30-8-1, 13) however the situation at the top of the WBA world rankings is a mess with WBA interim champion being David Sanchez (26-2-2, 20) and current "mandatory" challenger being Koki Kameda (33-1, 18). It's fair to say that neither of those parties, especially Kameda, would be happy at being over-looked for Tso.
Whilst we do know that Kono has mentioned Tso by name the Hong Kong star hasn't been mentioned by the champion since last year. In fact a recent interview by Kono has suggested he wants a Japanese opponent in his next defense and name dropped possible foes including former 2-weight world champion Akira Yaegashi (20-5, 10), former Flyweight champion Toshiyuki Igarashi (19-2-1, 11) and Sho Ishida (18-0, 10). Although no opponent has been signed for the champion as of yet he's expected in the ring in May.
Our Hong Kong source has speculated that a Tso Vs Kono bout would happen in July in Macau, if both men were to win their up coming contests.
(Image courtesy of http://sport-asia.com)