The manager also said United are "closer" to making signings.
Speaking after United beat Wigan Athletic 2-0 at Wembley to win the Community Shield, Moyes was asked how Rooney's shoulder injury prevented him being available while he is set to feature in England's friendly with Scotland at the same venue on Wednesday.
"I don't see why you think that's confusing. It's a big game for Scotland. You don't think I'm going to send England a fit player, do you?" the Scot joked. "I spoke to Roy [Hodgson, England manager] for probably two hours at different times. Roy knows the situation. Wayne has trained and some of you might not like hearing this but I didn't fall out with Wayne. Some of you wrote untruths. Anybody who wrote anything else is misleading their readers. He trained with the reserves [on Thursday and Friday] because it was his asking.
"He couldn't have contact because it was a shoulder injury. It was as a floating player which means he doesn't play for either team, just in case any of you are unclear what I mean about that. He played as a floating player so that he didn't get injured. Anyone who wrote anything else was mistaken.
"I'm quite enjoying talking about Wayne because I'm hearing so many of you getting it wrong and I know most of you. I think you're a bit cleverer than that but some of you aren't acting that way."
After underlining that Rooney was not for sale despite Chelsea's plan to return with a third bid after those for £20m and £25m were rejected, Moyes said: "I want him to join up with England. He trained with us yesterday. He's not ready and you'll probably see that during the game. He'll probably play a chunk of the game but he's had no football apart from 45 minutes against Real Betis in a friendly where he's hurt his shoulder. Apart from that he's got no match action.
"So you wouldn't expect someone in that condition to be playing for a long period. He's coming back, he's breaking himself back into the team and it will be great for Manchester United because hopefully he'll get some game time. He wasn't ready for today. But he's got a chance of being ready for Wednesday."
The United captain, Nemanja Vidic, questioned why Rooney would want to play for any other team, said: "I believe Man United is the biggest club in the world and I think there's no point to go anywhere [else]."
"There's so much speculation, so much talk about whether he'll leave or stay. He's at the best club in the world. I have to say in the last four years I was in that position as well. People were talking about me leaving the club. I'm still here and I'm enjoying playing for this club. Nothing has changed."
Moyes is yet to make a major signing since succeeding Sir Alex Ferguson this summer. "We're getting closer to signings," he said. "We're moving forward but the deadline is getting closer as well. Hopefully we are. If we don't I'm happy to go with what we've got. We had a lot of young English players today. We gave them the opportunity. It's always something that gets mentioned, giving young British players a chance, and there's quite a lot doing that at Manchester United."
Asked why United were interested in Cesc Fábregas, the Barcelona midfielder who last week stated he would stay at the club, Moyes added: "Because Manchester United go after the best players in the world and I think Cesc comes very close to that class."
Moyes is considering an official bid for Marouane Fellaini but the Scot denied United had any hand in the Belgian not being in the Everton squad for Sunday's 2-1 friendly victory over Real Betis at Goodison Park . Everton said Fellaini had an infected cut.
"It was a great header," he said of the Dutchman's opener. "Sixteen yards out and into the side-netting. He might not be renowned for that type of goal but it was a brilliantly guided header from a long way out.
"I've been really impressed with Robin. He's been easy to work with, he's taken on everything, he's been really receptive and helpful. We've tried to manage him at the right times by playing him for some minutes.
"He's so important that we have to look after him and we'll do that at the right times. He just showed today that he comes up with the goods again with his goals."
Van Persie is confident that United can retain the title. "We are the champions and based on that we are clear favourites. We're doing really well and I believe in this team," he told ITV. "I believe that we will compete until the end again. It's always nice to score, especially at Wembley. One day, one game and we've won a trophy, so it's good. I'm really glad for everyone."
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image: © Audrey Pilato