The Seattle Seahawks have reached agreement on a two-year, $15 million deal with former Detroit Lions defensive end Cliff Avril, a league source told ESPN NFL Insider Adam Schefter.

Avril received the Lions' franchise tender last offseason and didn't sign his one-year, $10.6 million contract until a week after training camp began.

Avril, who will turn 27 on April 8, finished last season with 9.5 sacks, 35 tackles and two forced fumbles.

One of the premier pass rushers on the free-agent market, Avril has 39.5 career sacks and 16 forced fumbles since 2008, when Detroit drafted him out of Purdue in the third round.

In Seattle, Avril joins a talented line that includes Chris Clemons, who tore his ACL in the playoffs, and 2012 first-round pick Bruce Irvin.

Getting Avril is another huge move for the Seahawks, who completed a trade for Minnesota Vikings wide receiver Percy Harvin on Tuesday.

Information from The Associated Press was used in this report.