Brazil coach Dunga praised Ronaldo's progress in his latest comeback and said on Thursday the national team door was open for the 32-year-old striker.
Ronaldo has scored 10 goals in 13 games for Corinthians since recovering from last year's knee injury at AC Milan and joining the Sao Paulo-based club.
"It's the first time since 2006 that he has managed to play more than 10 games in a row, so the trend is for him to progress," Dunga told reporters.
"Ronaldo has never stopped scoring goals," he added. "He knows his potential. There is one year between now and the World Cup for everyone to work and earn a chance."
The former AC Milan, Inter Milan, Barcelona and Real Madrid striker has not played for Brazil since the 2006 World Cup, having been plagued by fitness and form problems.
Brazil's next games are next month's World Cup qualifiers in Uruguay and at home to Paraguay. Dunga is due to name his squad on 21 May.Reuse content