Signing veteran Josh Tupou stops the bleeding up front, but his historical limitations highlight a looming depth crisis for John Harbaugh’s defense.

Less than a week after losing Roy Robertson-Harris to a torn Achilles tendon, they have added 350-pound nose tackle Josh Tupou.

Signing veteran Josh Tupou stops the bleeding up front, but his historical limitations highlight a looming depth crisis for John Harbaugh’s defense.