Defensive and struggles are two words that normally aren’t
associated with each other when it comes to the Pittsburgh
Steelers. But when it comes to the numbers, the Steelers defense
is one of the best in the league.  Pittsburgh ranks second in
the NFL in yards, allowing only 277.3 yards per game, and is the
best in the league against the pass.  Even the much-maligned run
defense ranks fifth in the league and has shown signs of getting
better in recent weeks.  So where are the struggles?  The
Steelers defense is only 12th in the league in points allowed at
22.0 points per game and they are tied with the Buffalo Bills
for the worst third-down defense in the league.  Besides
allowing more than a touchdown more per game than last season,
the Steelers defense has struggled holding fourth quarter leads,
blowing leads against the Denver Broncos, Oakland Raiders and
Tennessee Titans.  Why has the defense suffered such a drop-off?
There have been two major reasons: injuries and struggling
starters.  Justin K. Aller/G