The Italian is not allowed to have anything to do with the running of the club until 10 April. In accordance with the ban, he stepped down last month.
"I know Massimo well and it is his absolute intention to come back to Elland Road," former investment banker Umbers told Radio Leeds.
"He is a very good leader and he is passionate about Leeds.
"He wants to re-engage with fans, the council and the community and he is committed to that.
"He is the steward of this ship. I am the steward of it while he is away, but it is his ship."