Ryan Clark explains that Ben Roethlisberger will be scrutinized more after the departures of Antonio Brown and Le'Veon Bell. (0:59)

The Pittsburgh Steelers are working to complete a contract extension for quarterback Ben Roethlisberger before the NFL draft begins Thursday night, sources told ESPN's Adam Schefter on Tuesday.

Roethlisberger, who was drafted by the Steelers in 2004, is heading into the final season of the four-year, $87.6 million extension he signed in 2015.

The two sides have been talking since the end of the 2018 season and are getting closer to having a new deal in place, a source told ESPN.

Roethlisberger, who turned 37 on March 2, has two Super Bowl victories and ranks sixth in career passing yards (56,194) and seventh in touchdowns (363). He led the NFL in passing yards in 2018 with 5,129. The Steelers never have had a losing season with him at quarterback, and he is among the franchise leaders in career games played with 216.

Seattle Seahawks quarterback Russell Wilson became the highest-paid player in the NFL when he signed a four-year, $140 million contract extension last week.

ESPN's Jeremy Fowler contributed to this report.