Lawrence was optioned to Triple-A Tacoma on Friday.
Lawrence was heavily used this past week, most recently firing five innings Thursday against Colorado. Now that he's likely to be unavailable for a couple of days, the Mariners opted to send him back to the minors in order to bring fresh arms up to Seattle. Despite the demotion, Lawrence's strong showing Thursday should help him find his way back up to the big leagues whenever more bullpen depth is needed.