They point to a number of factors, including Houston's difficulty in making it through a full season without an interruption because of injury. He hasn't played an entire 16-game season since 2014.
The Chiefs believe Houston's preference for playing outside linebacker on the left side -- and their willingness to allow him to do so -- is another cause.
But this season they're planning to move Houston to various spots around the defense to best take advantage of his considerable skills.
"I want to be able to attack the weakest link," Houston said during offseason practice. "Everybody's team is different. Everybody's left tackle isn't All-Pro. Everybody's right tackle isn't All-Pro. Wherever the weakest link is, even if it's the guard, center or even tackle, I want to be on the weakest link."
Reestablishing their pass rush is a priority for the Chiefs, whose defensive backfield might need the help. The secondary is mostly rebuilt from last season. The Chiefs traded their No. 1 cornerback, Marcus Peters, and four of their other top five corners in terms of 2017 playing time won't return. Safety Eric Berry is back after missing most of last season, but he's coming off a torn Achilles tendon, lending an uncertainty as to how well he will play.
The Chiefs have struggled getting to the quarterback over the past two seasons, ranking in the bottom 10 after being in the top 10 in 2013, 2014 and 2015.
They're hopeful the healthy return of outside linebacker Dee Ford, who had 10 sacks in 2016 but missed more than half of last season because of a back injury, and the addition of Breeland Speaks in the second round of this year's draft will make a difference. They also have 2017 second-round pick Tanoh Kpassagnon at outside linebacker.
"He's an important guy to get back," defensive coordinator Bob Sutton said of Ford. "He's obviously a guy that has great skill. He has great ability to rush, a natural rusher on the edge. Those guys are hard to find. That would be a big addition.
"I think there's a good core group there. If we keep pushing them along and elevate them, we'll be fine."
The Chiefs also are expecting more from Houston. Sending Houston after the quarterback more often -- as opposed to dropping him in coverage -- could help. He has been in coverage frequently over his career in comparison to some other top rushers. Only once since joining the Chiefs in 2011 has Houston gone after the passer on more than 77 percent of his plays. That happened in 2016, when Houston's rush rate was 87 percent. But Houston was limited that season to five regular-season games because he was coming off knee surgery and he clearly wasn't right physically that year.
Houston rushed the quarterback on 77 percent of his pass plays last season, when he had 9.5 sacks. His career percentage is 72 percent. As comparisons, Denver's Von Miller rushed the passer 93.3 percent of the time last season and 82.5 percent in his career. Oakland's Khalil Mack went after the QB 95.1 percent of the snaps last season and 89.3 percent of the time in his career. Houston lined up as the left outside linebacker last season on 750 of the 901 defensive snaps on which he played, or 83 percent. Miller played his primary position, also left outside linebacker, 82 percent of the time. Mack played most of his snaps as a left end, but only on 52 percent of his plays.
The Chiefs suggest Houston might have similar numbers this season.
"He likes to line up on one side [but] we've got to get our best player on their worst offensive lineman, wherever that may be," outside linebackers coach Mike Smith said. "You can't just get comfortable on one side. You're asking him to go across the line and that's what we're doing."
The Chiefs also plan to similarly maneuver their other top pass-rusher, Ford, to get the most favorable matchups.
"Dee is the same deal," Smith said. "If there's [an opposing] tackle that's bigger and a little bit slower, Dee's got one of the best get-offs in the league. Go line up on him. If the tackle is a little bit smaller, Justin will go tear him up a little bit."