Expect a drop-off for the Panthers

Steve Smith, now with the Ravens, forced 26 missed tackles during the past two seasons. Grant Halverson/Getty Images

Now that we are almost a month into the new league year, we have seen plenty of player movement throughout the NFL via free agency. That's left some teams with big holes in the roster in areas that had previously been a strength.

Some teams have been able to fill those holes -- some have even gotten stronger -- but others haven't managed to keep up, either through salary-cap struggles or missing out on their targets. With that in mind, here's a look at the five units that have lost the most this offseason, including a look at each player's 2013 grade (listed in parentheses; for a description of PFF's grading system, click here). You can find our take on the most improved position groups here.

Carolina Panthers: Offensive line

Players lost: Jordan Gross (+33.5), Travelle Wharton (+20.5), Geoff Hangartner (-1.4), Bruce Campbell (0.0)
Players added: None

There's no real way to sugarcoat this: Losing Gross and Wharton really hurts the Panthers. They will go into the 2014 season with a new starter at both spots on the left side of the line after having that be one of the strongest parts of the team last year. Gross was an excellent player throughout his time in Carolina and was good up to the very end, finishing his 10th and final season as our third-highest-graded offensive tackle.