Before leaving, Maxwell went 2-for-4 and scored the winning run in the Royals' 2-1 victory over the Tigers. Since joining the Royals in a trade with the Astros, he's hit .406 (13-for-32) with two doubles, a triple and three home runs.
To replace Maxwell, left-handed pitcher Will Smith was recalled from Omaha for the sixth time this season and was eligible for the Friday night half of the doubleheader.
In his previous callups, Smith pitched in seven games for Kansas City, with a 1-1 record, a 3.26 ERA and 20 strikeouts against one walk in 19 1/3 innings. For Omaha, he has a 6-3 record, four saves, a 3.00 ERA and 99 strikeouts and 24 walks in 87 innings.
In effect, Smith also will replace lefty Danny Duffy on the pitching staff after his start in Friday's first game. Duffy is allowed on the roster as the 26th player for a doubleheader.
Maxwell is the third Royals player to leave the team this year because of family deaths. Catcher Salvador Perez and pitcher Wade Davis were the others.
The departure of Maxwell reduces the Royals to three outfielders but newly-arrived infielder Emilio Bonifacio is also a seasoned outfielder. In fact, he started Friday night's nightcap in center field.
Center fielder Lorenzo Cain is on the 15-day disabled list and third baseman Mike Moustakas has been sidelined by an injury. Manager Ned Yost is well aware that their absence has hurt.
"It makes a difference, it does," Yost said. "Moose has been swinging the bat really well. Our defense with Cain in there is better; he's arguably one of the best center fielders in the American League. And count his offense, too. It hurts, but you've got to find ways to cover it. That's what good teams do."
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.