Southampton boss Ronald Koeman has labelled Slaven Bilic's decision to take a weakened squad to Romania for the second leg of their Europa League third round qualifier as "crazy".

Southampton will begin their own clash against Dutch side Vitesse Arnhem tonight as the firm favourites, leading the Eredivisie outfit 3-0 already.

On the other hand, the Hammers go to FC Astra Giugiu level at 2-2 and needing a vastly-improved performance to progress to the play-off round.

With West Ham opening their Premier League campaign at Arsenal on Sunday, Bilic is expected to name a second-string side for the trip to Europe.

“That is all a part of the job,” said Bilic when asked about the side which would face Astra. "I have to make decisions, my decision is not to lose the game but to win it.

“There have been many unusual things but we knew from the start that it is not an ideal pre-season because we have had qualification, starting from the bottom.

“I don't like the excuse, I don't see it as a problem, it is a situation and I'm trying to cope with it.

“We want to show respect but not to jeopardise the more important competition.”

Only three members of the squad travelling to Romania are likely be part of the Croatian’s first team plans this season – Carl Jenkinson, Kevin Nolan and Manuel Lanzini.

The Premier League begins this weekend and these Thursday night fixtures come at an understandably awkward time for both English sides. However, when asked about Bilic’s decision Koeman did not hold back.

“It is a crazy thing to think about,” he stated. “To throw everything away in the start of the Europa League legs. I don't like that.

“I am a person who likes to win always and I hate losing. I hate to lose and that mentality needs my players as well.”