Chien-Ming Wang vows he'll return to the mound by May. Wang, who turns 31 in March, hasn't pitched in the big leagues since undergoing shoulder surgery in July of 2009. The Nationals signed him a to a one-year, $2 million contract last offseason, but he never made a big league appearance. He recently re-signed a new contract with the Nationals that includes a $1 million base salary and $4 million in performance incentives.