PITTSBURGH -- Safety Terrell Edmunds was discussing the Pittsburgh Steelers' search for interceptions when he abruptly switched subjects, without switching at all.

"The library is very low. We've got to read up on some books," Edmunds said.

Apparently the "library" is the defensive backfield's stash of interceptions, which sits at a paltry four entering Sunday's matchup with the Los Angeles Chargers. The Steelers' defense is tied for 24th in the NFL with six interceptions, and no Steeler has more than one.

But while Edmunds calls it a library, veteran Joe Haden and others call interceptions "books" based on the card game spades.

Whatever the background, what's clear is the Steelers need and want more books.

"Joe just started saying we need to get some books, and he was talking about interceptions, so we said, 'You know what, let's start calling it books,'" corner Mike Hilton said. "We've got to get books this Sunday."

The numbers say disrupting Philip Rivers' rhythm will be an arduous task. Rivers' 115.7 passer rating is third best in the NFL behind the power of 3,119 yards, 26 touchdowns, six interceptions and a 69.5 completion percentage. Many believe he's got an outside chance at an MVP for leading Los Angeles to an 8-3 start.

But there's one thing about Rivers' game Hilton loves.

"Philip likes to throw the 50-50 ball and let his guys make plays," Hilton said. "Basically, he feels: Our guy is better than you. He's giving his guys the chance to go get it. As a defense, that gives us more opportunities. We have to take advantage of it."

Pass breakups aren't going to be enough, and after too many near picks, the Steelers know their minus-7 turnover ratio, seventh-worst in the league, must change. The Steelers sit at minus-6 over the past two games.

Haden, who's considered to have the best hands among the defensive backs, estimates his crew has dropped six or seven interceptions this season. Safety Sean Davis nearly corralled a ball in the dirt against Jacksonville in Week 11. Edmunds said with a smile he's "dropped three, or two, or one."

The Steelers' defense is largely about discipline, which means taking gambles on passing lanes can get the entire defense beat for a touchdown. And after a shaky start to the year, the Steelers have rebounded with a No. 6 ranking in total defense, averaging 22.6 points allowed per game. They've done that by not taking chances, following assignments and letting the front seven punish quarterbacks for a league-high 39 sacks.

But adding more turnovers would change the dynamic, Edmunds said.

"We've been doing our thing and winning, but that splash play is going to take us to the next level," Edmunds said. "The next level where everybody's talking about us."

Players say the defense had several interceptions in practices this week, which they hope serves as a springboard of muscle memory.

Even elite quarterbacks such as Rivers know the NFL truism: Turnovers can come in bunches.

"One day you can have zero, next day you can have four," Hilton said.