Andrade only returned to training at the beginning of this month after two operations on his left knee last season.

The Portugal international signed for Juve last Summer but broke his kneecap in only the fourth game of the Serie A season.

The former Deportivo La Coruna and Porto player needed two operations after the first was unsuccessful and admitted he had considered retiring.

Now his future is in question again after an accident in training.

"The incident occurred on July 10 while he was training on his own in Pinzolo, to the same knee bone operated on twice last season," read a statement on the Juve website, www.juventus.com.

"A new surgery will be necessary to synthesise the bone tissue; likely to be carried out on Monday July 14 by Doctor Martins and his team in Lisbon.

"The player is expected to stay out of action for a few months."

Reports in Italy state Andrade's season is definitely over and also suggest it could spell the end of the 30-year-old's career.