The Steelers signed coach Mike Tomlin to a two-year contract extension through the 2012 season, with an option year in 2013.

The extension was expected because the Steelers' policy has been to sign a coach before he begins the final season of a contract. Tomlin is only the Steelers' third coach since 1969, after Chuck Noll (1969-91) and Bill Cowher (1992-2006).

Tomlin is 31-17 in three seasons, with two division titles, an AFC championship and a Super Bowl victory. During the 2008 season, he became the youngest coach — he was 36 — to win the Super Bowl. His new contract is expected to at least double his average of $2.5 million per season under his current deal.

•The results of an independent study commissioned by the NFL and the players' union show modern helmets perform better than those from a decade ago, though it stressed that no helmet can prevent concussions. … According to reports, defensive end Marques Douglas agreed to terms on a $2.5 million, two-year contract with the Dolphins.