That job instead will go to Geno Smith -- as long as tests on his knee don't reveal a serious injury.
The Seahawks signed Lynch to a futures deal in January after the 2016 first-round pick of the Denver Broncos was out of football in 2018. They then signed Smith in the spring to compete for the lone backup spot, as Seattle keeps only two quarterbacks on its 53-man roster.
Lynch could end up on Seattle's practice squad if he goes unclaimed on waivers. The Seattle Times first reported that he was being waived on Friday.
Smith looked like the more capable of the two throughout the offseason and the summer, though Lynch started to gain ground after an impressive showing in the first preseason game against Denver. He took a hard hit to the head from Minnesota Vikings cornerback Holton Hill in Week 2 that sidelined him for the third game. In Thursday night's preseason finale against Oakland, Lynch completed 1 of 7 passes for 4 yards. One of his incompletions was a near interception that could have gone for a pick-six had the defender not dropped it.
Lynch's final line in three preseason games: 18-of-37 for 180 yards, a touchdown and no interceptions. He ran for another score.
Smith, meanwhile, went 4-of-7 for 107 yards and a pair of touchdown passes Thursday but couldn't finish the first half after his knee got rolled up on. He missed the second preseason game after surgery on his knee to remove a cyst.
Coach Pete Carroll called Smith's latest knee injury a "little tweak" and said the team will know more in a couple of days once he gets checked out. Smith said his knee felt fine postgame but added that he might need to get an MRI.
In three preseason games, Smith went 18-of-34 for 282 yards, two touchdowns and no interceptions. He also rushed for a touchdown.
Said Carroll of Smith: "He looks in control of the offense. He gets it. He really understands it. So that's a real positive."
J.T. Barrett was the fourth quarterback on Seattle's 90-man roster.
The Seahawks also waived Shalom Luani, defensive end Logan Tago and rookie running back Xavier Turner on Friday, a source told ESPN, and veteran defensive back DeShawn Shead posted on Twitter that he'd been released.