The Seahawks placed cornerback Tre Brown on the reserve/physically unable to perform list Sunday, and waived four players: tight end Cade Brewer, linebacker Aaron Donkor, cornerback Jameson Houston and running back Ronnie Rivers.

NFL teams must reduce their rosters to 53 players by Tuesday at 1 p.m. PT.

Brown, a fourth-round pick in last year's draft, started three games as a rookie before suffering a season-ending knee injury. Brown had previously been on the active/physically unable to perform list, meaning he took up a spot on the roster, but the move to the reserve list opens a roster spot while requiring him to miss at least four games before he can return.

Donkor, who is from Germany, joined the Seahawks last year as part of the NFL's International Player Pathway Program and spent the season on the practice squad. Teams receive roster exemptions for players in that program prior to the cutdown to 53 players, so Donkor has not counted against the 90, 85 or 80-player limit. If Donkor clears waivers, he could join Seattle's practice squad with an exemption that would keep him from counting towards the 16-player limit.

Brewer initially signed with the Seahawks as an undrafted rookie free agent out of Texas following the 2022 draft, was waived during camp, then re-signed last week. Houston, who went undrafted out of Baylor in 2020, signed with Seattle earlier this month. Rivers, who went undrafted out of Fresno State, signed with Seattle last week, and carried the ball twice for 6 yards in Friday night's preseason game at Dallas.