Gera returned to the Hawthorns on a Bosman from Fulham.
Hodgson revealed: "The change of management almost spoilt the deal for us in so much they made it clear that when the new manager (Martin Jol) came in and Ray Lewington got promoted to first-team coach, they really wanted to keep him but luckily he still wanted to join us.
"Zoltan made up his mind he wanted to work with me again but he had to listen to plenty of overtures to try and change his mind.
"It's a big signing for us. Zoltan is one of the big signings of this transfer window and I'm expecting big things from him.
"He will provide extra competition in an area where we already have a lot of competition.
"And we already have an extra player in Graham Dorrans this year, who didn't play much of a part for me last season."