The Patriots will be without a key staffer this weekend as defensive coordinator Terrell Williams will be away from the team for a few days, per Ian Rapoport of NFL Network. Though head coach Mike Vrabel is a former defensive coordinator, albeit only for a single season, he will entrust the defensive play-calling duties to inside linebackers coach Zak Kuhr, according to ESPN’s Mike Reiss.

Williams, a defensive line coach with the Lions for the past two seasons, was visiting home in Detroit in May of the offseason when he experienced a “health scare.” Doctors advised him to stay there instead of returning to New England for the start of rookie minicamp. He declined to give any details about the specifics of his health, though he said he would in the future.

In June, reports declared an uncertain timeline for the first-time coordinator’s return. At that point, Kuhr had been leading the defense throughout OTAs. Kuhr revealed at that time that his coordinator was making sure to check in on his staff and players daily via video conference. Williams’ determination to stay connected to the team paid off when he made a late-July return to New England in time for training camp.

This week’s newest update is unfortunate to see. Williams will be undergoing medical testing, but with so little information on his issues so far, Rapoport points out that there’s hope the absence will be unrelated to his previous health scare. Vrabel informed the media that he is expecting an update next week, “and then (they)’ll go from there.”