West Ham captain Mark Noble hopes Marko Arnautovic will stay this month.
But he admits it was "realistic" for the Austrian to be considering a big-money move to China.
West Ham last week rejected a £35m bid from a Chinese Super League club, believed to be champions Shanghai SIPG, for Arnautovic, whose brother and agent has said he wants to leave.
"I spoke to him (before the match) and he said, 'Mark, whatever happens, it is out of my hands, but as long as I play for this team, I am going to give 100pc'," Noble said.
"You saw that (against Arsenal). Marko has got a reputation of maybe being a little sulky but, let me tell you, he is a great lad around the dressing room. Do we hope he doesn't go? Of course, he's probably our best player.
"But I always think it is such a short career. You work until you are 35 and then you have got to find another living. You go to China for five years on £400,000 a week, you don't."