Officially, Sako has been out of contract since the end of last month, but a report in the Birmingham Mail confirmed that Wolves boss Kenny Jackett invited him to take part in pre-season.
Sako spent three years at Molineux, netting 38 goals in 124 games, and helping the club out of League One and back into the Championship. Generally considered one of the best players in the second tier, he has been linked with a move to the top flight since his contract expired at the end of last season.
The Telegraph has claimed that Aston Villa and West Brom have been tracking his availability ahead of potentially moving for Sako, whilst Leicester have also been linked with the winger - as per the Birmingham Mail.
Although his future has yet to be decided, with all three clubs delaying a potential move for a number of weeks, it is still expected that he will secure a Premier League transfer. And, even if he does not, it appears as if Sako has no intentions of returning to Wolves this summer.