JACKSONVILLE, Fla. — The Jacksonville Jaguars will be without half their starting secondary against Pittsburgh on Sunday night.

Safety Reggie Nelson (knee) and cornerback Drayton Florence (groin) will miss the game, coach Jack Del Rio said today.

Nelson bruised a knee two weeks ago at Indianapolis when he collided with teammate Brian Williams and sat out last week's game against Houston. Florence strained his groin on the final series against the Texans. Both players missed practice all week.

The Jaguars already were thin in the secondary: Top backup cornerback Scott Starks injured his right knee against the Colts and was placed on injured reserve.

"You'd like to have your guys — we have three of our top six defensive backs out — but you have to go on," Del Rio said.

Cornerback Will James, beaten on long pass plays against the Colts and Texans, and safety Gerald Sensabaugh are expected to start against the Steelers.

Jacksonville's defense could get a boost with the expected return of linebacker Justin Durant. He missed the last two games because of a groin injury, but practiced all week and was listed as probable Friday.

Still, the secondary issues could put increased pressure on a defense that ranks 24th against the pass and has just five sacks in four games.