The Chinese Super League club has confirmed on their website that a deal had been reached with Turkish club Beskitas, with varying reports suggesting anywhere between €11 and €16 million for a transfer fee.
The arrival of Ba could either assist Cahill at the Chinese giants, or spark a transfer away from the club he joined in February of this year.
Cahill has endured a rough start in China, scoring only once in his first 13 games before netting two goals in Shanghai's last two outings.
The Australia and Everton legend may be on the outer at the club given there are rules which limit the amount of foreign players allowed in each squad.
News of Cahill's potential availability would no doubt spark the interest of a host of A-League clubs.