Brazil's matches against Italy and Russia are billed as friendlies but could be an acid test for midfielder Kaka's hopes of playing in his fourth World Cup next year.
Brazil coach Luiz Felipe Scolari, taking charge of his second match since being re-appointed in November, said on Wednesday that Kaka will be under the microscope as he continues to look for his ideal team for the Confederations Cup in June and next year's World Cup.
Scolari tested 32-year-old Ronaldinho in last month's friendly against England but the former Barcelona and AC Milan player failed to impress, as he missed a penalty and was substituted at halftime after a ponderous display.
The coach, known as 'Big Phil', had already made it clear he would test former World Players of the Year Kaka and Ronaldinho separately before deciding whether they were suitable for 2014.
The Real Madrid player gets his turn against Italy on Thursday and Russia on Monday.
"The idea is to bring him (Kaka) on during the (Italy) game and maybe let him start in the match against Russia," Scolari told reporters.
"We want him to show his potential and whether he is in the right condition or not. We want to observe how he blends in with the other players, compare his characteristics with the other players."
Kaka, hampered by injuries over the last few seasons, played for Brazil at the 2002, 2006 and 2010 World Cups. After the latter tournament, he did not play again until last October when he performed impressively against Iraq and Japan.
Scolari said Ronaldinho, whose gradual decline has been widely blamed on his partying lifestyle, would have another chance for forthcoming matches in April and May.
"Then we will analyse if they can play together, if they can not play together, or if one will be chosen, or neither," he said.
Scolari led Brazil to their fifth world title in 2002 and was re-appointed after Mano Menezes was surprisingly sacked.
Menezes had painstakingly rebuilt the team, bringing in younger players and introducing a new style of play largely inspired by Barcelona, but with a Brazilian touch.
Scolari, who prefers a more pragmatic approach, has only a handful of games to find his preferred line-up as he tries to build a team capable of winning a sixth World Cup on home soil next year.
"I have had one training session, one game and one more training session," he said. "I have to make the most of these to test things which I think could work during the games.
"The matches are our training sessions."