Walcott may get the chance to lead the line for the Gunners in place of suspended Olivier Giroud today against United.
He said: "When you lose someone like Robin - one of your best players - it's obviously difficult to replace the amount of goals he scored and what he did for the team. But we've coped with it well.
"Everyone is sharing the goal load and we haven't relied on one player.
"We're in a similar situation to last year, when we finished third."