Fans' favourite Petrov, who played more than 200 times for Villa and earned more than 100 caps for Bulgaria, has recovered and last month said he wanted to resume his career.
"Aston Villa Football Club is pleased to confirm Stiliyan Petrov will take part in pre-season training at first-team level," a club statement said.
Petrov will join new manager Roberto Di Matteo and the rest of the squad for a training camp in Austria as Villa prepare for life outside the Premier League after being relegated.
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"Stan will report next week with the rest of the group," the club said.
Petrov posted a photo of himself looking fit and healthy on Twitter recently, saying "getting fit is hard work but nothing is impossible".
He set up a leukaemia and cancer charity -- the Stiliyan Petrov Foundation -- during his time spent recovering.
(Reporting by Martyn Herman; editing by Clare Lovell)
