The San Diego Chargers' 2013 season suffered a big blow more than three months from kickoff when linebacker Melvin Ingram suffered a torn ACL in his left knee during OTA work Tuesday.

Ingram, the Chargers' first-round pick in 2012 from the University of South Carolina, was expected to be a key cog in the 3-4 defensive scheme that was already questionable in the pass rush department.

The Chargers could have a tough time finding a suitable replacement, given that the best available pass rushers in free agency - John Abraham and Dwight Freeney - are both more suited as 4-3 ends rather than 3-4 linebackers.

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Terry McCormick covers the Titans for TitanInsider.com