Defender Carragher, who stood down in frustration three years ago, was named in Capello's 30-man provisional squad on Tuesday after a two-month courtship.
"I want the best players and one of those is Carragher," Capello told a news conference at Wembley. "We started two months ago and he said 'perhaps'. Two weeks ago he said 'yes'. He's a really, really good player."
Capello said he had not given Carragher any guarantee that he would be in the 23 but with only one other right back, Glen Johnson, in the squad and Carragher offering cover there as well as in central defence, the 32-year-old seems certain to go.
Midfielder Scholes, 35, won the last of his 66 caps six years ago but Capello has been very impressed with his performances for Manchester United.
"We tried to convince him but he said he preferred to stay with his family," he said.
Capello said decisions over two players had been left right until Tuesday morning.
The first was midfield regular Gareth Barry, who is out of action for several weeks with an ankle injury but got the nod after a meeting with medical staff.
"I put him in the 30 because the next medical check will be May 24," he said. "After that we will decide what we can do."
The other was Bobby Zamora, who leads the line for Fulham in Wednesday's Europa League final against Atletico Madrid, but he did not make the cut.
Zamora has needed pain-killing operations on his troublesome Achilles before recent games and told Capello he would almost certainly need an operation.
"It was one of the last decisions I made. It was up to him, he can't train every day and plays always with injury," he said.
Capello said he had no concerns about the fitness of defenders Ledley King or Rio Ferdinand, whom he was assured by Alex Ferguson would be fine.
He also dismissed the idea of selecting Owen Hargreaves, who has played just 45 seconds for Manchester United this season.
"I spoke to him twice but he hasn't played for 18 months so I can't select him," he said.
Uncapped midfielder Adam Johnson was a surprise inclusion.
"He is a very interesting player, he played very well in the second part of the season with Manchester City. He's one of the most interesting young players in the Premier League and I want to check him in training and in matches," Capello said.
England, who begin their World Cup campaign against the United States on June 12, play Mexico in a Wembley friendly on May 24 before travelling to Austria for high altitude training, including a friendly against Japan in Graz on May 30.
He will announce his final 23-man squad on June 1 and any subsequent changes will be allowed only in the case of injury.
Capello was relaxed and assured when running through
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