It seems that Chelsea were willing to offload the German captain in the summer but only his £130k per week wages prevented the deal going through.
It's been reported in Spain that Real coach Bernd Schuster is still keen to land the 30-year-old midfielder.
He said: "The door is not closed, but it's essentially a question of money.
"His Chelsea contract is extraordinary, no Real player is paid like him and we don't want to set a precedent."
Schuster says that talks between Chelsea and Real took place in the summer but collapsed when Ballack's wages were revealed.
Schuster addded: "His footballing qualities are always there, and they will still exist in six months."
Suggesting that if Ballack fails to convince Chelsea he has a future, then it's probable he will be on his way out of Stamford Bridge.
Ballack signed on a free transfer in 2006 and is currently recovering from an ankle injury.
He was ommited from Chelsea's Champions League squad.
Chelsea say he would not have figured in matches, other believe it was a tactic to keep his transfer value high as he will be eligible to play Champions League football for another club this season.