Hollmann's agent Ahmed Abbas told FilGoal.com that the former Ahli tactician reached a preliminary agreement with Zamalek to take over at the Cairo giants.
"Hollmann was a frontrunner to coach Ismaili but talks between both parties stalled due to the club's instability," Abbas added.
Ismaili chairman Saad Al-Gendi resigned from his post on Tuesday.
With the elections due in August, it is unclear whether the Egyptian Higher Council for Sports (HCS) will appoint a temporary board to manage Ismaili.
Zamalek Job
If Zamalek successfully conclude negotiations with Hollmann, the 58-year-old will succeed Dutchman Ruud Krol, who resigned at the end of the season due to family reasons.
Hollmann had a spell with Zamalek's arch-rivals Ahli in the mid 1990s. He helped the Red Devils win three league titles and one Egyptian Cup.
He then coached several teams in the United Arab Emirates, including Al-Nasr, Al-Shabab and Al-Wehda.