Zylstra reverted to the Lions' practice squad Monday, per the NFL's official transaction log.
Zylstra operated as the Lions' No. 3 option at tight end behind Sam LaPorta and Brock Wright in the team's 52-14 win over the Titans in Week 8, failing to record any offensive stats while playing 13 of the team's 48 snaps on that side of the ball. He did record a tackle in punt coverage while playing 20 snaps with the special-teams unit. Zylstra can still be elevated one more time before he'd have to be officially signed to the active roster.