Chicago Cubs shortstop Starlin Castro has agreed to a seven-year contract extension worth $60 million, a source told ESPNdeportesLosAngeles.com.

The contract covers four years of arbitration eligibility and three years of free agency, and includes a $16 million option for 2020. Castro, 22, was projected to qualify for salary arbitration as a "Super Two" player at the end of the year.

When contacted by ESPNdeportesLosAngeles.com, Castro's agent, Paul Kinzer, said he would not comment on the Dominican shortstop's new contract because the sides are still in the process of negotiating.