Brown has a sprained toe that he suffered in the win over Tennessee. Graham is nursing a hip injury.
“He got a hip pointer about a few weeks ago, missed a little time in practice in the preseason
Kubiak was cautiously optimistic that Graham would return to practice on Friday, and said "hopefully he’s back out there tomorrow."
Graham has caught a touchdown in each of the Texans' first two wins, and has seven catches for 57 yards in 2013.
Brown, meanwhile, hasn't been ruled out for Sunday's game at Baltimore.
"Like I told you yesterday, I have no problem, Duane can play football without practicing," Kubiak said. "He’s played a lot of snaps. He knows our offense better than anybody. We’ve left him inside and we’ll just push toward the weekend and see where he’s at.”