Luke Weaver has arrived in Seattle after a shaky stint in Cincinnati, while Bryan Woo came off the injured list and Emerson Hancock has his stay extended.
Emerson Hancock left the Seattle Mariners' game against the Houston Astros on Sunday due to a shoulder injury, but JP Crawford is rejoining the lineup.
Kevin Kelly suffered a sprained ankle and will miss at least the next two weeks for the Tampa Bay Rays, who were already dealing with plenty of injures.
Garrett Whitlock hasn't pitched for the Boston Red Sox since before the All-Star break, and he will move from the rotation to the bullpen upon his return.
Right shoulder tendinitis kept Greinke out for the past two weeks, but he will return to the mound with his sights set on reaching 3,000 career strikeouts.