The Steelers have exercised their fifth-year option on linebacker Ryan Shazier, a source tells Albert Breer of The MMQB (on Twitter). The Steelers technically had until May 3 to make the call, but they didn’t see any point in delaying. 
There was no real question that the Steelers would trigger Shazier’s fifth-year option. The 24-year-old (25 in September) has been a key cog in the Steelers’ defense for the past two seasons, starting 24 of 25 regular season games played. He had roughly identical production in 2015 and 2016, tallying 87 total tackles and 3.5 sacks in each campaign.
For his work, Pro Football Focus ranked Shazier as the 32nd best linebacker in the NFL last year, tying him with Mark Barron of the Rams and Danny Trevathan of the Bears. His 78.4 overall score was a career high. With his arrow pointing up, the Steelers will retain their rights to him through at least 2018.