The AFC South champions won 11 of their opening 12 games in 2012, before losing three of their final four.
The quarterback told Texans Radio: "No-one had higher expectations or knew what we could do as a team more than us as players. We put so much into it. We work so hard to achieve a certain level of success. And we fell short of our goal, inside the locker room and out.
"I think as a whole group, we need to just be more consistent. We lost our consistency level that we had maintained for the better part of the season, just our ability on first down to be successful and put ourselves in manageable situations, make our third downs manageable.
"When you're not staying on the field offensively and scoring sevens, teams like New England, teams like Indianapolis the way they were playing at the end of the season, they're tough teams to beat, especially on the road. So we've got to figure out that level of consistency and maintain that."
The Texans were knocked out of the playoffs in the divisional round, losing 41-28 to the New England Patriots.