Barbis told Goal that Keet has already made up his mind about leaving the Students whom he has been with for the past three seasons.
While Barbis confirmed huge interest in Keet's services from overseas clubs, he wasn't able to reveal the names of the teams that his agency has been talking to at this stage.
"At the moment we've got a firm offer from Portugal; there's one club that we've got there, and we are meeting with another club next week," Barbis told Goal.
"We've got interest from Sweden as well that he has been presented to, and we have spoken to some clubs in Qarabag. There's one of the clubs that spoke to us directly," he continued.
"And obviously with Afcon now, which means the focus is on [the tournament], and we will make the decision by the end of the month the latest," added Barbis.
"So, he is definitely leaving South Africa. His mind is made up in Europe and that's where he wants to go and that's where he will be playing next season," he concluded.
Keet spent five seasons in Belgium with KV Kortrijk between 2011 and 2016 before returning to South Africa three years ago.
However, Keet had always maintained that his first preference would be to return to Europe.
The 29-year-old keeper will leave the Clever Boys having won three major trophies with them between 2016 and 2019.
In 2016, Wits beat Sundowns to the MTN8 trophy before being crowned PSL champions at the end of the 2016/17 season.
Keet was instrumental in helping the Braamfontein-based side lift the Telkom Knockout Cup in December 2017 when they edged out Bloemfontein Celtic in Durban.
Last season, Keet made 26 league appearances and kept 10 clean sheets. He conceded 26 goals in the league.
The Cape Town-born player is expected to star for Bafana at this year's Africa Cup of Nations (Afcon) tournament which gets underway on June 21.
South Africa will begin their Afcon campaign against Cote d'Ivoire in Cairo, before meeting Namibia and Morocco as they look to reach the knockout stages.