Hu, 26, hit .317 with four homers in two separate stints with Triple-A Albuquerque last season, also batting .130 in 23 at-bats for the Dodgers. Hu is a .299 career hitter over eight Minor League seasons and a .191 lifetime big league hitter in 173 at-bats spread amongst four seasons.
A native of Tainan City, Taiwan, Hu was named MVP of the Futures Game back in 2007.
Antonini, 25, made a splash in Spring Training back in 2009, but he has struggled in the two seasons since. Last year, Antonini posted a 4.32 ERA in 23 starts for Double-A Binghamton and a 5.11 mark in six starts for Triple-A Buffalo.
The Mets now have seven middle infielders on their 40-man roster, including Hu, Justin Turner and recent Rule 5 pick Brad Emaus, all of whom will presumably battle for a bench role in Spring Training.