The 22-year-old spent the second half of last season on loan at the Bundesliga club where he impressed, scoring five times in 17 appearances and attracting the interest of a host of other German sides in the process.
His form prompted Borussia Dortmund to submit a reported £5million bid during pre-season, but former boss Paolo Di Canio decided to reject it in the hope that Ji would prove his potential at the Stadium of Light.
The South Korea international's Sunderland contract is set to expire next summer, but Reuter admitted it is unlikely that Augsburg will attempt to secure a return for Ji before the end of the campaign.
"It is no secret that Ji had a great season playing for Augsburg. But I do not want to talk so much about new players," Reuter is quoted by the Sunderland Echo.
"Basically, we are keeping our eyes and ears open, but I'm not a fan of transfers during the winter break."