German national soccer team coach Joachim Loew (Photo: Reuters)
Ballack made the last of his 98 appearances for Germany in the pre-World Cup friendly with Argentina in March 2010 before suffering back-to-back injuries.
Having damaged his ankle playing for Chelsea in last May's FA Cup final, which kept him out of the World Cup, Ballack then fractured a leg in September after returning to play in Germany for Bayer Leverkusen.
He returned to action in January, but Loew has repeatedly said the battling midfielder will need to win back his place in the national side.
Ballack has now played the full 90 minutes in four of Leverkusen's last five consecutive victories with his side second in the league and he was expected to play in Sunday's clash at German champions Bayern Munich.
"He is improving physically and is in good shape," Loew told German daily the Cologne Express.
"That's what I expected. He makes a good impression, he exudes authority and calm on the pitch."
Germany next play fellow World Cup semi-finalists Uruguay in a friendly on May 29 before Euro 2012 qualifiers against Austria and Azerbaijan in June, which could seal their place in next year's tournament with the Germans top of the group.
Loew has said he will talk to Ballack to discuss the situation, but the veteran faces a tough task as standing in his way are Bayern Munich's Bastian Schweinsteiger and Real Madrid's Sami Khedira.