Buffalo Bills star linebacker Kiko Alonso has suffered what's believed to be a torn anterior cruciate ligament that will end his season before it ever began.

"We have learned tonight that Kiko Alonso injured his knee while working out in Oregon," Bills general manager Doug Whaley said in a statement. "We do not have the details at this point, but early indications are that it may be significant."

A magnetic resonance imaging exam will be performed to confirm the initial diagnosis.

Alson also had hip surgery this offseason.

Alonso recorded 159 tackles, 10 for losses, two sacks, four interceptions and a forced fumble.

It's a huge loss for the Bills' defense.

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Aaron Wilson covers the Ravens for The Baltimore Sun