The record signing told the Birmingham Mail, "The manager hadn't really said anything to me and I don't think he has said anything to Dean so it's up to the manager," said Carson, who joined Albion from Liverpool for an initial £3.25million last month.
"It's a decision for the manager and we can only do what we have got to do.
"He has told me he is going to make a decision before the Arsenal game.
"He is going to wait and see how we do and the is one game left so it us up to both Dean and myself to work hard in the next couple of weeks.
"I thought we both did what we had to do well last night (against Walsall) and the rest is down to the manager.
"It was nice to get another 45 minutes and it's always nice to make a couple of saves which I was pleased with."