DETROIT — The Detroit Lions need linebackers, and the Seattle Seahawks had one to spare.

Detroit acquired Pro Bowl linebacker Julian Peterson on Saturday from the Seattle Seahawks for defensive tackle Cory Redding and a fifth-round pick in next month's NFL draft. Both players must pass physicals to complete the trade.

The Seahawks gave Peterson a $54 million, seven-year contract three years ago after their Super Bowl appearance in Detroit. Peterson became an expensive asset because linebacker Leroy Hill got $8.4 million guaranteed this year with a franchise tag and Lofa Tatupu signed a $42 million contract a year ago.

During its winless season, the lack of talent at linebacker was one of Detroit's glaring problems.

The Seahawks, meanwhile, had one of the league's best trios with Peterson, Tatupu and Hill.

After being Seattle's only player in the Pro Bowl, Peterson was dealt after a five-sack, 83-tackle season. He had 9.5 sacks and 10 sacks in his first two years with the Seahawks, the highest totals of his nine-year career.

The San Francisco 49ers drafted Peterson with the 16th overall pick in 2000 after he starred at Michigan State. The native of Temple Hills, Md., has 46 career sacks and eight interceptions.

Detroit is taking on a lucrative contract by adding Peterson, but the franchise is also taking a big one off the books.

The Lions gave Redding a seven-year contract worth nearly $50 million two years ago when they slapped the franchise tag on him after he had a career-high eight sacks.

But Redding had only one sack in 2007 and three last season as a team leader of the NFL's first 0-16 season.

Detroit drafted the native of Houston with a third-round pick in 2003. The former Texas standout was used sparingly as a rookie before starting every game in four straight years and 12 last season. Redding has 16 sacks and 162 tackles over his six-season career.