Johnson said he is scheduled to get the stitches from two incisions removed early next week.
"I wish I could go out there and try to run around today to see how it feels," he said Friday. "But I have to just wait until I get the stitches out and then I'll go all out."
The five-time Pro Bowl selection says he has felt great since Tuesday's procedure and is confident he will be back soon. He described himself as a fast healer.
"I haven't felt any pain with any of the exercises I've been doing ... so I'm pretty pumped," he said. "I've been bending my leg and everything. The only thing that really bothers me a little bit is where I have the stitches. So I think once I can get those out and the cuts close up I'll be fine."
The Texans (3-1) host Oakland (2-2) on Sunday and then play at Baltimore on Oct. 16.
Johnson was injured Sunday in a win over the Pittsburgh Steelers. He recounted his thoughts when he was hurt after catching a pass in the second quarter without being touched.
"I was scared," he said. "I really couldn't explain what it was, I just felt pain. You see I was grabbing my leg when I was on the ground."
Johnson isn't walking with any sort of a limp, a fact that has caused several coaches to comment on the "pep in his step" this week. He said an old injury led to a "pretty big lump" of scar tissue that had been causing pain behind his knee off and on for some time.
"I had a lot of scarring around my tendon and that was the irritation that everything was coming from, so they had to go in and clean it up," he said.
Johnson has 25 catches for 352 yards this season to lead the team. Jacoby Jones will fill in for Johnson this week and the Texans can also go to tight end Owen Daniels, who has 14 receptions for 182 yards and three scores.
"We're being challenged right now from a numbers standpoint as a football team," coach Gary Kubiak said. "That's what this league is about -- trying to find a way each week to regroup and put your best group on the field to win another game. We've got to pass the test."
Johnson hates sitting out when the Texans are playing so well. But he believes the team is better equipped to deal with his absence than in the past when he was injured.
"The whole attitude of the team is totally different than it used to be," he said. "Of course you don't want to lose anybody, but at the same time we know what's at stake for the team. Guys are going to go out and get the job done."