Ze Roberto apologises for Hamburg absence
"I'm sorry that I did not go to the training camp and that I took so long to tell the club about the reasons for this," the former Brazil international told the Bundesliga club's website.
"I've had some family problems which can only be resolved in Brazil. I ask the supporters not to doubt my reliability, something which has been a trademark of my career."
The 35-year-old, who joined from Bayern Munich in the close season and had been enjoying an excellent season, added that he had recovered from an ankle operation at the end of November.
Hamburg went into the winter break fourth in the Bundesliga, four points behind leaders Bayer Leverkusen.
Coach Bruno Labbadia said on Monday that the player would be fined for the incident.