Inter confirmed that Lucio and Maicon have returned to the club to resume pre-season preparations following their late summer break.
Lucio featured in Brazil's 3-2 friendly loss against Germany on Wednesday's night, while Maicon was not part of the match squad.
Both players were granted extra summer leave by Inter following their commitments at the Copa America last month.
The Brazilian duo have now returned to Italy and will resume training on Thursday evening as they start work for new coach Gian Piero Gasperini.
A statement on Inter's official website reads: "The Brazilians Lucio and Maicon, after their rest period and involvement with the national side have today [Thursday] returned to the Angelo Moratti training centre."
Maicon has been recently linked with a move away from Inter with reports suggesting he is being followed by Real Madrid and Manchester City.