Asked on ESPN980 why Campbell was a team captain and he wasn't, Portis replied: "I wonder the same thing. It's no disrespect to Jason, but everybody in that locker room will tell you -- you will never see Jason mad, you will never see Jason's tempo change."
Portis continued: "(He's) going to give you everything (he's) got. But as a leader ... it was always, 'Jason couldn't take control of the huddle,' or 'He didn't do this' or 'He didn't do that.' That wasn't Jason's character. ... I think Jason, you can't place so much on somebody who's not ready for that situation. I think Jason has enough trouble in getting the plays in and worrying about this, compared to controlling the huddle."
Portis told ESPN980 that Campbell isn't the type of player who would go to a coach and say, "'Well, we need to do this or we need to do that,' or 'This is how the players want it.'"
Campbell wasn't pleased about Portis' comments and responded to them during a Tuesday telephone interview with The Washington Post.
"How is he going to say I'm not a leader?" Campbell said. "I mean, that's just not true. To me, that's somebody who shows that they don't know what a real leader is. A leader is not someone who leads by the wrong example. A leader is someone who is trying to do the right thing and trying to lead by example, and not just [being] about themselves.
"There's a reason guys get selected as captains, and there's a reason guys don't get selected as captains. Obviously, he doesn't have the respect of the locker room to be a captain. For someone to try to take a shot at me at the end of the season, after they haven't even been around, only speaks about their character anyways."
Campbell informed The Post via text message Wednesday that Portis had called him to clear the air. The text read: "We're just going to move on. We don't want to have any issues out there between us for the offseason, so we're just going to squash all of this right now."
Portis also took exception to comments made by some teammates Monday about a lack of discipline this season and preferential treatment given to some players.
"Don't wait for the season (to be) over to say that's what the problem was," Portis told the radio station. "They could've came out and addressed those players and tried to stop it. But you wait until the season's over -- and then it's like a tell-all book came out."
Although other players didn't call out Portis specifically, he said: "You would think out of everything that came out, probably the first name that come to mind would be me. I never missed curfew. I ain't never left the hotel. I never did any of that. I think the only thing we did, there was a group of us that set up and played poker, and they broke that game up at 11 o'clock."
As for Shanahan, who will replace Jim Zorn in Washington, Portis described the coach -- with whom he spent two seasons as a Denver Bronco -- as "the perfect guy for the job" and a "straight shooter."
"If you're doing the stuff you're supposed to be doing, you're fine with him," Portis told the radio station. "If you're not, no matter how much you're getting paid, he's going to get you up out of there."
The Associated Press contributed to this report.