Giants coach Tom Coughlin says Beatty was diagnosed with a rotator cuff injury during his rehabilitation from a pectoral tear and will need surgery.
Beatty has been the starting left tackle for the most part since 2011. He tore a pectoral muscle in the offseason lifting weights and was placed on PUP to start the season.
The Giants had until Thursday to make a decision on activating Beatty.
First-round draft pick Ereck Flowers has replaced Beatty at left tackle and played well.
Coughlin also said that left guard Justin Pugh did not sustain a concussion Sunday. His headaches were from dehydration.
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