LAKELAND, Fla. (CBSNewYork/AP) — J.D. Martinez hit a a three-run homer to lead the Detroit Tigers past the Mets, playing without Jacob deGrom, 9-2 on Monday.

DeGrom had been slated to start for New York, but he was scratched because of back stiffness. He stayed in Port St. Lucie and threw a lengthy bullpen session Monday morning instead.

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Seth Lugo, filling in for deGrom, threw two scoreless innings. But relievers Robert Gsellman and Rainy Lara struggled, allowing seven of the Tigers’ runs. Gsellman surrendered three earned runs over two innings, while Lara gave up four in 2/3 of an inning.

Wilmer Flores went 3-for-3 with two doubles for the Mets to raise his spring average to .556. Catchers Kevin Plawecki and Johnny Monell each added two hits.

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Of being scratched, de Grom said Monday: “I think it’s more precautionary. I didn’t want to ride on the bus for a couple hours and then go pitch. I’m actually going to throw off the mound here.”

DeGrom, who was 14-8 with a 2.54 ERA in 2015, said the reason for his back pain might be a soft mattress. After a recommendation by Mets ace Matt Harvey, deGrom recently purchased a firmer mattress and had it overnighted.

“I had to switch something up and that seemed to work,” deGrom said.

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