The South Africa international has made it clear that he will be leaving Everton after rejecting a new deal with the club.
And with his current contract set to expire in the summer, the Toffees have been left with little choice other than to try and sell him this month.
They have now accepted bids from Tottenham and Chelsea as he looks set to depart this month.
But Everton No 1 Howard is confident Moyes and the club will cope without him.
"Steven has been our engine for the last couple of years," he told the Daily Mirror.
"There is no hiding from that. He has been our star player. But my feeling, having been at this club for so long, is that we just get on with it. We don't dwell on things.
"The gaffer David Moyes is really shrewd. He found Mikel Arteta, Tim Cahill and Steven Pienaar.
"There will be another. That's just the way it is here at Everton."
