HOUSTON -- Amobi Okoye will start at defensive tackle for Houston, but who will start beside him is anyone's guess.
Travis Johnson has missed all of camp after sports hernia surgery, and Frank Okam and DelJuan Robinson haven't shown the consistency coach Gary Kubiak wants. With two preseason games remaining, Kubiak needs someone to take the job. Soon.
The performance of the line will be key in the improvement of the entire defense. The Texans ranked third in total offense last season, but 22nd in defense and finished 8-8 for the second straight year.
Johnson was a first-round pick in 2005, but has yet to live up to expectations. His career has been marked by numerous injuries and Monday was the first time he participated in practice since camp began.
He only worked in the individual drills during the first 20 minutes of practice and Kubiak is unsure when Johnson will practice with the team.
"He's going to tell us," Kubiak said. "I'll go back and see how he did. I'll watch the film. He's going to have to have a certain conditioning level to get back on the field. We need to get him back out there to give him a chance to compete for a spot on this team."
Johnson started 14 games last season and 13 in 2007, but his absence has given Okam and Robinson a chance to prove themselves.
Kubiak called Okam impressive in Houston's first preseason game against the Chiefs, but he, along with the rest of the defense, disappointed against the Saints.
"Frank's had some bright spots," Kubiak said. "He's become a better player, but we're looking for that level of consistency and he was right in the middle of them (Saturday) as far as it not being good enough."
Okam weighed nearly 340 pounds when he arrived as a fifth-round pick last season after a largely disappointing career at Texas. He committed to improving this offseason and has dropped between 25 and 30 pounds from his 6-foot-5 frame.
He thinks being in better shape has helped his performance, but believes having a year of experience in the system has been more important.
"It is a little more confidence," he said. "The second year you figure out what's going on. That first year your head is all over the place ... with a year in you get to actually know what's going on with defense, recognize offensive schemes and be a player."
He appeared in five games last season and had just six tackles. Coaches would love to use his size in the middle of the line.
"There's a window there and his consistent play could very well land him a starting spot on this football team," Kubiak said. "But he's going to have to play better than he did (against New Orleans) and he knows that. But there have been some positives throughout this camp. He's moved forward."
With Johnson out, Okam has been competing with Robinson to play with the first team. Robinson was an undrafted free agent in 2007 and spent most of his first season on the practice squad.
His work ethic helped earn him a spot on the team last season. He appeared in each game, started three when Okoye was injured, and finished with 28 tackles.