KANSAS CITY, Mo. -- The Kansas City Chiefs will begin training camp next month without one of their most important defensive players. Outside linebacker Justin Houston, who had ACL surgery in February, won’t be ready to participate when camp begins in late July at Missouri Western State University.

“When you’re around him, you have this optimism he’s going to be back in a short period of time, but in reality it’s going to take a little bit," coach Andy Reid said Thursday after the Chiefs concluded their final offseason practice. “That’s OK. We’ve got other guys that will step in, step up for him at that spot until he gets back. The important thing is that he gets back and is healthy and that you don’t rush it and do something foolish with it."

Reid also sounded a note of caution with running back Jamaal Charles, who tore his ACL last October. Charles practiced two days this week, the only time he’s worked on the field with his teammates during the offseason.

Charles was given the day off on Thursday but Reid said that was precautionary and not because of any setbacks.

“We’ll have to see with Jamaal," Reid said. “You don’t want to take any steps back. He had two good days here and then we’ll just see how he does at camp. We’re optimistic about the two days. But let’s not rush him. We know what he’s all about. Let’s get him back to where he feels good and whatever timetable that is or how much he practices there, we’ll see day by day."

Though Houston won’t be ready for the start of training camp, he isn’t necessarily behind schedule for a possible return. Shortly after Houston’s surgery in mid-February, the Chiefs gave a best-case scenario for his return of six months. That would be mid-August, or about the time the Chiefs are wrapping up at camp.

Chiefs OLB Justin Houston is "a hard worker" and will be back on the field "when he's right," said coach Andy Reid. Troy Taormina/USA TODAY Sports

General manager John Dorsey said recently that Houston would play for the Chiefs at some point this year, though he wasn’t specific about when.

“That’s the feeling the kid gives you when you’re around him," Reid said of Houston, the Chiefs’ leader in sacks in three of the last four seasons and the co-leader in the other. “I don’t think any of us probably know but he makes you feel that way. He makes you feel like he’s going to be out there playing.

“I don’t know how much he’s going to do in camp. But, listen, he’s where he needs to be right now and he’s a hard worker. He’s bound and determined to get back. We’ll just see how it works out. There is no timetable. It’s just when he’s right, he’s right and we’ll roll."

The other starting linebacker, Tamba Hali, also didn’t practice during the offseason after having knee surgery. Reid indicated the Chiefs would also have to monitor his progress when camp begins.

Houston’s replacement is Dee Ford, who left practice early on Wednesday because of what the Chiefs are saying is tendonitis in his knee. Ford returned on Thursday but did little work. The starting outside linebackers Thursday were Frank Zombo, a veteran backup, and Dezman Moses, who was signed as a free agent earlier this month.