Zylstra was activated from Detroit's practice squad Friday, while fellow Lions tight end T.J. Hockenson (thumb) was placed on IR after season-ending surgery.
With Hockenson out for last week's 38-10 loss to Denver, the Lions called on Zylstra to handle 63 percent snap share and six targets in his first taste of non-special-teams action in the NFL. He caught just two of the six passes for 18 yards, with fellow tight end Brock Wright adding three catches for 20 yards on five targets (and 56 percent snap share). It's possible one separates from the other in the coming weeks, but the most likely scenario for this Sunday against the Cardinals is another timeshare.