The 28-year-old midfielder took part in an individual session at the Etihad Campus, according to a video released by the reigning English champions on Friday.
Rodri, who tore his anterior cruciate ligament during a 2-2 draw with Arsenal, was initially considered to be out for the rest of the English season. It was estimated that he could return for the Club World Cup, which begins on June 14 in the United States.
Earlier this month, City manager Pep Guardiola declined to give a date for his compatriot's return: "The most important thing for him is that he recovers well, he is no longer a teenager but he still has several years of playing time ahead of him and he will be able to return if he recovers well."
The absence of the player who won the European Championship with Spain last season has been particularly noticeable at Manchester City, who have already been eliminated from the Champions League and are only fourth in the Premier League, 20 points behind leaders Liverpool.