Astros manager Bo Porter said both players were available on Thursday -- Altuve to hit and Barnes to run.
"If Altuve can hit, he can hit, but he probably wouldn't be able to run 100 percent," Porter said. "Hopefully, he'll get a full day of treatment and it heals, and he's much better the next day.
"With Barnes and [swinging] the bat, you don't want to take any chances. It stiffened up on him last night and you have had to pinch-hit for him to get him out of the game. I told him the same thing I told Altuve, 'You guys take it easy today, get all your treatments and if we can keep you out of the game, we'll keep you out. If you're pressed into it, you're pressed into it.'"
Barnes said he can still feel tightness in his back while swinging the bat, but said he would be available for any duty if needed.
Brian McTaggart is a 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.