The left-handed Cubs pitcher said he's using a unique technique to improve his throwing to bases.
The 25-year-old outfielder will miss opening day against the Indians.
Shoulder inflammation has kept Marcus Stroman from making his spring debut, and Troy Tulowitzki is still nursing an ankle injury from July.
Boston Red Sox pitcher Drew Pomeranz suffered a mild flexor strain.
Stewart pitched eight seasons with the Orioles and played a key role on the pitching staff of the team's last World Series champion in 1983.
The team had originally said the Seahawks quarterback wouldn't appear in Grapefruit League play, but had a change of heart.
In 32 starts in 2017, Pomeranz was 17-6 with a 3.32 ERA, 1.35 WHIP and 4.0 WAR.
The New York Yankees may be disliked again, but that is fine by owner Hal Steinbrenner.
With the acquisition of Giancarlo Stanton, some are calling the Yankees "The Evil Empire" once again, and Steinbrenner is OK with that.
Tony Clark said commissioner Rob Manfred made his changes to pace of play without any approval from the MLBPA.