Ortiz (neck) will begin a rehab assignment with High-A Wisconsin on Thursday, Curt Hogg of the Milwaukee Journal Sentinel reports.
Neck inflammation has kept Ortiz on the injured list since July 3, though his neck issues can be traced back to late June. The Brewers haven't officially stated how many games they plan on having the third baseman play in the minors, though the fact he's headed to High-A Wisconsin may indicate the team wants to keep him nearby for activation once he's eligible to return from the IL on Friday.