Chiefs trainer Rick Burkholder said the normal rehab period for such a procedure is between six and 12 months.
"We're hoping just because of his work ethic and he's been a fast healer in the past that's not the case and that he'll be able to play this season,'' Chiefs coach Andy Reid said. "It's too early to be able to tell on that."
Houston is one year removed from a 2014 season in which he led the NFL with 22 sacks. His 2015 season was interrupted by a knee injury that caused him to miss the regular season's final five games. He returned to play in both playoff games, though he wasn't effective and didn't play a full role in either game.
Houston went to see noted orthopedic surgeon James Andrews after the season for the knee injury, which the Chiefs said was to the posterior cruciate ligament. Andrews performed arthroscopic surgery on Houston's knee in early February.
"When Dr. Andrews took a look inside his knee, he determined his ACL was intact,'' Burkholder said. "It just wasn't functioning. He didn't do anything at that moment, brought him out of surgery. We all got on the phone, discussed everything and decided to have his ACL fixed."
Burkholder said Houston had the ACL surgery on Feb. 16.
"Right now he's in the middle of the process of total rehabilitation for an ACL injury," Burkholder said. "It was a little bit tricky because his ACL wasn't torn, but it wasn't functioning the way it should. So Dr. Andrews fixed that.
"It's too early to tell where he's at right now," Burkholder said. "But he's on the road to recovery."
The Chiefs recently re-signed their other outside linebacker, Tamba Hali.