The New York Mets have offically put Jason Bay on the DL. He will be eligible to return to the active roster on April 9. ((Jim McIssac/Getty Images))

New York Mets left fielder Jason Bay will start the season on the disabled list because of a strained left rib cage.

Bay had tests Wednesday in New York. Bay felt discomfort on his left side Tuesday and was pulled from the lineup.

The move is backdated to March 25, so he'll be eligible to return April 9. Outfielder Lucas Duda was placed on the active roster in Bay's spot Thursday.

The Mets also officially placed ace Johan Santana on the 15-day DL. He's sidelined until at least midsummer after shoulder surgery.

The Mets open the season Friday at Florida.