"He was fine," Porter said.
Fowler has been on the disabled list since June 27 with a strained right intercostal muscle. Expect him to play at least one game in the field for Oklahoma City before being activated, but that could happen as soon as Monday.
"When you play and you're playing consecutive days and we don't have any ill effects from what put you on the disabled list, you're ready to go," Porter said. "He's not down there to prove he can hit. He's down there to prove he's healthy."
Fowler, in his first season in Houston, was hitting .270 with six homers and 24 RBIs and a .377 on-base percentage.
Brian McTaggart is reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.