Upson joined West Ham from Birmingham last week.
He said: “There is no antipathy to Steve. Whatever has happened, my relationship with him is fine.
“I’ve spoken to him. We thanked each other for the last four years and we both move on. I know his gripe is with the board and that’s what he told me.
“I hope that West Ham will play Birmingham in the Premiership next season. That would be ideal.”
He added: “There are still a lot of games to go and, if this team had a bit more belief, it’s got the quality and the players to stay in the Premiership.
“We have to turn that corner but it’s not panic stations. We go again next week.”