Their first-round pick, receiver Will Fuller, is the team's only draft pick who remains unsigned.
A decorated quarterback at Ohio State, Miller changed positions before last season to better prepare himself for his NFL future. Coming off two significant shoulder injuries he suffered before the 2014 season, Miller's arm wasn't at full strength to start the 2015 season. Furthermore, the Buckeyes, coming off a national championship with Miller hurt, had two other quarterbacks who played well in his absence: Cardale Jones and J.T. Barrett.
The Texans are hoping to use Miller's unique athleticism in what's often a very creative Texans offense. He could be used for gadget plays early in his Texans career, and coach Bill O'Brien and general manager Rick Smith have faith that Miller can be a strong receiver.
O'Brien has experience with players making this transition, having coached Julian Edelman in New England. Edelman was a college quarterback who had his first 1,000-yard receiving season in 2013 and had 692 yards in nine games last season.
As these deals are relatively simple these days, there's no need for concern about Fuller not being signed yet. All of the draft picks have attended the Texans' voluntary sessions even before signing their contracts.