Capello has decided on his final Russia squad
Capello's men continued their preparations for Brazil 2014 with a 1-0 win over Slovakia in a friendly on Monday.
The Italian wants to see his squad, who face Belgium, South Korea and Algeria in Group H, continue training together, even if he has made up his mind on who will miss out.
"I'm really pleased with all of my players' work in the training camp," Capello told a news conference.
"In the match with Slovakia we've seen the high level of intensity that we will likely face at the World Cup in Brazil. I'm happy that none of my players were injured.
"I've already determined the 23-man squad for the World Cup but I want all of my 25 footballers to carry out preparations all together until the deadline."
Aleksandr Kerzhakov netted Russia's only goal against Slovakia in St Petersburg, but Capello felt his team were tired.
The former England coach also believes his side can be much better in attack.
"We showed well-organised play on Monday, it's a good starting point," Capello said.
"But we can definitely play better, much better in attack. It's obvious that after a series of very intensive practices last week my players lacked freshness against the Slovaks.
"And I'm even more happy to give the two young players (Maxim Kanunnikov and Pavel Mogilevets) the chance to make their debut in the national team."