Manager Alex Cora said Thursday that Schreiber (shoulder) will begin a rehab assignment this weekend, Mac Cerullo of the Boston Herald reports.
If all goes according to plan, Schreiber will be back to begin Boston's upcoming series with the Mets on July 21. The 29-year-old reliever has been on the shelf since May 15 with a right shoulder strain, and he put up a 2.12 ERA and 1.29 WHIP through 17 innings before getting injured.