RENTON, Wash. -- The Seahawks' linebacking unit will be without Leroy Hill for at least a couple of weeks.
Hill will miss at least the next two games -- Sunday at San Francisco, then Chicago -- with a lower stomach or groin injury. He was injured in the first quarter of a 28-0 win against St. Louis on Sunday.
"Leroy's made so many plays for us," Seahawks linebackers coach Zerick Rollins said. "Anytime you lose one of your starters, it hurts."
The only fully healthy starting linebacker is Aaron Curry.
Will Herring, a third-year special-teams player, will start for Hill.
And the Seahawks signed D.D. Lewis, who was released at the end of training camp, to help bolster the unit. The eight-year veteran started two games for Seattle last season as an injury fill-in. He will backup the middle and outside linebackers.
A person familiar with the deal said it's for the remainder of the season. It is worth $701,176, a prorated portion of the veteran minimum contract. The person spoke on condition of anonymity because the team does not discuss monetary terms of contracts.
Seattle waived rookie free-agent defensive end Derek Walker to make roster room for Lewis. The team had been carrying 11 defensive linemen on the roster, more than it usually does.
Herring started the first game of his career at the end of last season, when Hill was out with a pinched nerve in his neck.
Last summer, Herring's knees and ankles were so swollen his legs were inflexible, forcing him to miss training camp and the first six weeks of the regular season. Doctors determined Herring's autoimmune system was malfunctioning and causing the joint inflammation.
Although they prescribed twice-per-month shots of autoimmune inhibitors, Herring said he hasn't taken the shots since late December. He said the condition has vanished.
"It was scary," he said. "It definitely made me realize how blessed I am to be here and have my health."
Copyright 2009 by The Associated Press