I don't know if James Casey will start if Owen Daniels isn't ready to play, but he's coming on strong and can be as good as Daniels. The Texans will probably use Dreessen over Casey, at least at the beginning of the season, but Casey is a great athlete, a lot like Rob Gronkowski of the Pats. From Weenieworld:
Texans TE James Casey set a preseason franchise record with eight receptions in Thursday's game against the Bucs. Casey topped the record held by Andre Johnson on his way to 81 yards. He's a good bet to pick up extra playing time early in the season with Owen Daniels on a snap count. Casey won't be worth drafting in redraft leagues, but remains a Dynasty "hold" with Daniels entering another contract year.