Complex sentence: On December 15,2012, Lannan signed a one-year, $2.5 million contract with the Philadelphia Phillies that includes up to an additional $2.5 million in performance bonuses.
Split into simpler sentences: On December 15,2012, Lannan signed a one-year, $2.5 million contract with the Philadelphia Phillies. He could also receive an additional $2.5 million in performance bonuses.