Despite injuries, Pittsburgh Steelers offensive line still ranked in Top 10 for 2015

The Pittsburgh Steelers were dealt a difficult hand, in terms of injuries, in 2015. No unit might have been impacted more than the offensive line. All-Pro center Maurkice Pouncey broke his ankle in the second preseason game against the Green Bay Packers, and was lost for the season. Midway through the season Kelvin Beachum tore his ACL, also having him lost for the season.

The "next man up" philosophy for the Steelers certainly was fulfilled by backups Cody Wallace and Alejandro Villanueva, but how would the unit rank among the other NFL offensive lines? Pro Football Focus ranked all the offensive lines in the NFL, and they have the Steelers at 10th.

See what was said about the Steelers' offensive line:

10. Pittsburgh Steelers (8th)

Pass-blocking rank: 7th

Run-blocking rank: 23rd

Penalties rank: 28th

Stud: A strong year from guard David DeCastro is something to be expected these days. 2015 was no different.

Dud: Cody Wallace may play with a nasty streak that a lot of people like, but there was a whole lot more to not like. You don't see centers give up as much pressure as he did, draw as many flags as he did, or be at the center of so many bad blocks in the running game.

Summary: You take out Wallace and replace him with Maurkice Pouncey, and you're looking at a group that could challenge the top three. Replace Alejandro Villanueva with Kelvin Beachum, and they could be the best. This line has really transformed over the years, and it's only injuries that saw them drop down the rankings in 2015.

The summary from PFF couldn't be more spot on. Add Pouncey and a more polished left tackle in Beachum and you have yourself one of the best offensive lines in the NFL. Nonetheless, moving forward this unit has some serious questions.

Beachum and guard Ramon Foster are both free agents, and their futures with the organization could leave the Steelers with some gaping holes not only at the starting positions, but in depth. Sure, Villanueva could be the starting left tackle next season, he certainly showed tremendous improvement this season when given repetitions, but who would be your "swing tackle" next season? Chris Hubbard? I'm pretty sure Ben Roethlisberger might want someone a bit more qualified protecting his blind side of another left tackle goes down.

Foster might be the biggest free agent for the Steelers no one is talking about. At a time when the interior line could be elite with Pouncey in the fold, Foster and David DeCastro were the glue which kept the line together. The offense is only as good as the offensive line, and although they were good in 2015, they certainly have some questions to be answered heading into 2016.