PITTSBURGH — Casey Hampton was asked after the Steelers’ third preseason game whether he can remember what it was like to be “a bubble boy.”

He could not.

“I never was a bubble boy,” said Hampton.

However, he became one the next night. One of the “insiders” at the NFL Network insinuated that Hampton will be cut this week. And, just as the laughter had died, someone from Yahoo.com said the same thing.

So, since these are national reporters, and all must be as they say, it appears that Hampton is now officially on the bubble.

“There’s a first time for everything,” he said.

Of course, he knows the “reports” are someone’s idea of attracting attention, but there’s no joking when it comes to the real bubble boys. They’ll be putting their careers on the line tonight at 8 p.m. at Carolina, where the Steelers and Panthers wrap up their preseason schedule.

“Leave it all on the field,” quarterback Ben Roethlisberger advised the bubble boys, or players who are on the “bubble” that is the 53-man roster. “It may be your last time to prove to the Steelers coaches what you have. Treat it like it’s your Super Bowl and leave it all on the field and no regrets.”

Arnold Harrison plays that way even if it’s a morning practice in May.

The undrafted Harrison made the practice squad on sheer will in 2005, and was promoted to the roster for the Super Bowl. On Halloween 2006, he tore up a knee, but made it back to play in 13 games and the playoffs in 2007.

Harrison tore up his other knee a year ago in this Carolina preseason finale, and it took away a step he couldn’t afford to lose. He’s just now getting it back.

“You’ve got to be patient with yourself,” he said. “In the spring, you knew it would take time. You know it’s a process and you have to allow yourself time. I came into camp in really good shape and I made it all the way through and I practiced every practice and I did pretty well, and every game I’ve been more and more productive. I’ve been getting closer and closer to the quarterback.

“At first I thought it might’ve been a timing thing, since I haven’t played a game in a full year. But in Game 3, which was an important game, I went out and played pretty well, and I played hard. I’ve just been praying a lot and working hard and knowing my assignments, and hopefully that will get me over the hump.”

Harrison’s character is responsible for him even having a chance tonight. Since neither Bruce Davis nor Patrick Bailey has seized that last linebacker spot, Harrison can make a real run.

Frank “The Tank” Summers might not be that desperate. This bubble boy just needs to get on the field.

“Yeah,” offensive coordinator Bruce Arians said in agreement. “For me.”

Certainly, the coaches need to see Summers, who practiced Tuesday for the first time in two weeks. His last full practice had been the goal-line scrimmage in which the offense erupted for five touchdowns in seven plays. Summers was the fullback and batted 2-for-3. The next morning, in “a young guy’s practice,” the coaching staff used Summers at both backfield spots, from which he was running, catching and blocking. The special teams coach then had him cover punts, and that’s when Summers pulled a hamstring muscle. He missed two games, and when asked for an assessment of Summers’s return Tuesday, Arians said, “I haven’t seen him in so long it’s hard to say.”

Summers was asked if he needs to get on the field this week.

“I need to get on the field every week, but, yeah,” he said.

Is this his last chance?

“I don’t know if you’d look at it like that,” he said. “I take every game the same way because, if I didn’t, that means I didn’t approach every game with the right state of mind.

“I’m focused, just like I was in the first preseason game against Arizona. Just looking forward to it, obviously, since I’ve been out for two weeks. But I’ve never missed a game before. This is a first. All you can do is stay mentally sharp and stay prepared while you’re out, so all I’m doing now is putting the physical aspect of it back into the game.”

So, he didn’t push it this week to return?

“Obviously this is important, being the last preseason game,” Summers said. “I just need to show up and play like I know how.”

Keiwan Ratliff and Ryan Mundy, and Brandon Williams and Shaun McDonald, and Jeremy Parquet and Jason Capizzi, they know what The Tank’s talking about. It’s the bubble boy’s credo.