Injuries that sidelined two starting defensive backs for a game against a division leader could have crippled most NFL teams. That's especially true for one that has spent much of its financial resources on offense. The Steelers, though, overcame some hiccups by the substitutes in the secondary to limit the Tennessee Titans to two touchdowns in a 40-17 victory Thursday night that kept them atop the AFC playoff race. With Joe Haden out with a fractured fibula and Mike Mitchell missing with an ankle injury, the Steelers weren't forced to plug in rookies or untested backups against the first-place Titans. Instead, they turned to two former NFL starters, a sign of the depth in their secondary that is uncommon in the salary-cap era. And the backups made significant contributions in the Steelers' fifth consecutive win, which came as no surprise to linebacker Ryan Shazier, the defensive playcaller. “When they come in,” he said, “we expect them to make plays.” Coty Sensabaugh, who started for three teams before joining the Steelers in March, replaced Haden and had an interception that led to a first-half field goal and 13-7 lead. Robert Golden, who lost his starting job to strong safety Sean Davis last season, replaced Mitchell at free safety had five tackles plus an interception that led to the final field goal in the 23-point rout. “We know who is coming in and what they can do,” Shazier said. “We just played our defense. It doesn't matter if starters are in or the last man on the depth chart. We have everybody ready for the game. They are in the same meetings everyone is in, so it's not like they are getting shorter knowledge.” Sensabaugh and Golden were part of a secondary that intercepted four passes — matching the total for Steelers defensive backs through the first nine games. It was the first time since November 1997 that the Steelers had four interceptions in a game. Mike Hilton and Davis had the others, with Hilton's also leading to a Chris Boswell field goal.