Cook (strained right lat) will begin his rehab assignment for Peoria in the Arizona League on Sunday, Bob Dutton of the Tacoma News Tribune reports.

EDGE Analysis

Cook has not pitched at all in 2016. If he can successfully complete his rehab without any setbacks, he could be a nice addition to a Mariners bullpen that has struggled over the past couple of weeks leading up to the All-Star break. Cook, who had a great run as a reliever for Oakland from 2012-2014, will look to regain his velocity and command after a very disappointing 2015 with the Athletics and Red Sox organizations.