It's possible that a roster spot could be made for Harris by releasing veteran fullback Thomas Tapeh, who wasn't as forthcoming about his health as the Vikings would have liked, Childress insinuated, when the Vikings signed him to a five-year, $6 million free-agent contract.
"We went through our regular process in looking up Thomas and everybody we bring in, from the tape work to the film work to the physical that he had. All those things are incorporated. The doctor's put hands on him. He had an X-ray," Childress said.
"We just didn't feel like all the questions we had asked, that we got conveyed all the information we needed."
Childress wouldn't say for sure if the Vikings would release Tapeh, but he was participating in Wednesday afternoon's practice.
If the Vikings would sign Harris, who had 96 tackles and 2½ sacks for the Vikings in 2006, it would be an interesting battle between him and Dontarrious Thomas, who re-signed with the Vikings earlier this week.
"I think we're both physical and we both know this defense," Thomas said after finding out about the team's interest in Harris. "We both are familiar with the defense and familiar with the scheme. We both bring that to the table. He brings more veteran leadership because he's been in this game longer. As far as myself, I'm just going out and whatever happens happen. I'll just put my best foot forward."
"I think they're a lot similar," said linebacker Heath Farwell, who is out for the season with a knee injury but played with both Harris and Thomas in the Vikings' system. "DT has been in this system. They both know it. Napo has started several games in the Tampa-2 system, but so has (Thomas). Give or take, DT is great against the pass. Athletically, he's very athletic. Napo is good against the run. They're both going to provide different things. They've both got different leadership things. (Thomas) is probably one of the most popular guys on the team – everyone loves him. That's a big factor."
While Harris left after the 2006 season after playing under then-defensive coordinator Mike Tomlin, Thomas played under Leslie Frazier's version of the Tampa-2 defense last year with the Vikings.
"Being with (Frazier), I definitely have more familiarity with his style and his scheme. But Napo is a great guy and he's been a great backer," Thomas said. "Basically Cover-2 is Cover-2 and all the backers do the same thing. You've just got to go out and play."
Thomas also has the advantage of playing numerous special teams while Harris didn't play special teams while he was with the Vikings, Thomas said.
But, despite the potential for more added competition, Thomas said he isn't surprised by the Vikings' move to bring Harris in for a physical.
"It's always like that. If you've been in the game long enough, you see there is constant competition week-in, week-out," Thomas said. "I've been in this long enough now to know what's going on. If you're going to worry about that, you definitely won't be able to play, won't be able to focus on what you can do and what you can control."
Childress was unsure how the whole Tapeh saga would play out.
"They are just going through all the rules and regs (regulations) that they go through internally, administratively," he said.
Asked what that means, Childress said: "Hard for me to tell. I don't know what the end play is, but I just know that there is a dialogue between our people within the building and I would assume Thomas – I've talked to Thomas – and his agent, etc."
When a reporter said that sometimes the next step is a transaction, Childress replied, "Yeah, we'll just have to see how that works out internally."