The Ravens had a difficult decision to make with veteran receiver Mike Wallace. They could pick up his contract option, which would count $8 million against the cap, or cut him and save $5.75 million in cap-space.
Baltimore decided to pick up his option, as per Jeff Zrebiec
Eight million is a sizable chunk of change, but it was something the Ravens needed to do. Wallace was Baltimore’s only proven receiver and could not afford to lose him. If he were to be released, it would not be long until he signed with another team.