He has now seen his side fail to win all but one of the last eleven games in all competitions, and he says there is a distinct lack of confidence among his players at the moment which is causing him concern.
“The start was good,” said Koeman.
“We were the dominant team and went 1-0 up but then starts the problem.
“We had some bad mistakes in our positions and poor communication.
“The first goal is not good an in my opinion you need to defend that inside and outside and then it’s not really that easy a cross.
“Then of course in the second half, the set plays killed us today.
“Until today we were good at defending set plays but of course they had taller players and they make their productivity better.
“We did everything, we took the risk and maybe the big problem at the moment is that if we’re down then we have a good reaction but why not earlier in the game.
“In my opinion the team is too passive and not pro-active and that’s maybe fear at the moment.
“Of course I’m worried as the manager at the moment because we have a really bad run of results but I see a lot of similar problems in the team that I tried to explain now.
“I know of course it’s maybe a lack of confidence but if you start the game well you need a better belief in the team and not going back and defending and nervous.”