Earl Thomas gets 4-year extension

Earl Thomas is about to become the NFL's first $10 million-a-year safety.

Thomas and the Seattle Seahawks have agreed to a four-year contract extension worth $40 million, sources confirmed Monday to ESPN.

NFL.com reported earlier Monday that Thomas agreed to the extension, which makes him the league's highest-paid safety in terms of average salary.

The deal includes $27.75 million in guaranteed money, sources confirmed to ESPN.

Thomas received praise from Pro Bowl cornerback Richard Sherman.

Congrats to my brother @earl_thomas SETTING THE BAR!! #LOB http://t.co/oCSbPvF23O

- Richard Sherman (@RSherman_25) April 29, 2014Thomas, 24, recently completed his fourth season with the Seahawks and was named to the Pro Bowl for the third consecutive year.

He is widely regarded as the best safety in the league, and now his salary will reflect it.

Former Buffalo safety Jairus Byrd signed a six-year, $54 million contract with New Orleans last month that made him a $9 million-per-year safety. The deal included $28 million in guaranteed money.

Prior to Monday's deal, Pittsburgh's Troy Polamalu had the highest average salary of any safety at $9.867 million.

Thomas, who will make $4.625 million in base salary in the final year of his rookie contract, recorded 105 tackles and five interceptions last season and was one of the top defensive players during Seattle's run to the first Super Bowl championship in franchise history.

ESPN NFL Insider Adam Caplan contributed to this report.