[Kansas City.com] The bus emptied, and another top draft pick wasn’t with the Chiefs as they arrived at training camp.

Defensive end Tyson Jackson, the No. 3 overall pick in April’s draft, remains unsigned and did not travel with the team as it starts a pivotal preseason. The Chiefs are expected to undergo a conditioning test today before beginning practice Saturday, so there’s still time for Jackson to arrive in time for the start of two-a-days.

Not that first-year coach Todd Haley seemed all that nervous Thursday.

“I’m just going to worry about guys that are here,” Haley said.

The problem for Haley and the Chiefs is that, the more time Jackson is unavailable, the less time they’ll have to polish that new defensive scheme. Kansas City is planning to use a 3-4 front, and Jackson was drafted with the notion that he’ll be a load-bearing player as the team makes that transition. He’s one of a handful of Chiefs players who fit the 3-4 prototype, and any practice without the rookie could hinder a team that isn’t in the mood for setbacks.