Cook reverted to the Cowboys' practice squad Monday, per the NFL's transaction log.
With Ezekiel Elliott not making the trip to Atlanta for Sunday's game due to disciplinary reasons, Cook had a chance to earn a larger role in Dallas' backfield, but Rico Dowdle (55 of 77 offensive snaps) handled most of the work, and Hunter Luepke (17 snaps) was the next most-utilized RB option. Meanwhile, Cook was on the field for six offensive snaps and turned his two carries into eight yards. As long as Dowdle is healthy, Cook may not hold much sway in the Cowboys offense, even when Elliott isn't available.