IT was a victory that took Celtic to the verge of the knockout stages of the Europa League.

But Virgil van Dijk has still revealed he was disgusted by his side's display against Astra Giurgiu on Thursday night.

Indeed, the centre-half has even gone so far as to brand the 2-1 win over the Romanians at Parkhead as their worst performance of the entire season.

Having lost 4-1 to Legia Warsaw in a Champions League qualifier and been beaten 1-0 by Hamilton at home in the SPFL Premiership that is saying something.

But the Hoops looked disjointed at the back and toothless up front for the much of the match in midweek - so the straight-talking Dutch defender may have a point.

And Van Dijk has warned the Scottish champions they can't afford to play like they did in their Group D fixture again if they want to progress further in Europe.

"It was our worst game of the season," he said with admirable honesty. "We were so bad that we made them look good.

"Every chance they got was due to a mistake by us. But, at the end of the day, football is about winning. We won the game and that is the most important thing.

"I really don't know what the problem was. It was difficult to say why we didn't play well. I have no clue at all. We need to forget this game and move on.

"We all wanted to play the same football as we had against Ross County at the weekend. But we started off really poorly and didn't get going. I don't know what the reason for that was.

"It was maybe the only game this season that we were very, very bad in and won. It was good because we are almost through. We need to keep focusing on winning.

"I think we have mixed feelings. Yeah, we played badly and everybody knows that it was our worst game of the season. But we won and that is what the fans want as well."

Van Dijk continued: "Of course, they want to see good football, entertaining football, but it didn't work out the other night. We know what we are capable of and that is what we are going to try to do.

"If you win then it is fine, of course. But we know we can play better. We still have confidence in ourselves. We will work hard and train hard to get ready for tomorrow's game with Kilmarnock.

"Everybody wants to play at their best, put in a great performance and win the game with good football. It didn't go too well football-wise against Astra, but we won the game and we have seven points now and that is almost enough to go through.

"We certainly didn't take them lightly. We had a good preparation and we knew that they had the quality to make it hard for us. So we didn't underestimate them. But we can't play like that again."

Van Dijk played for Celtic against European giants AC Milan, Ajax and Barcelona in the group stage of the Champions League at Parkhead last season.

The Glasgow stadium was packed full of Hoops supporters on all three occasions and they created an atmosphere that is renowned around the continent.

Celtic Park was only half-full - as it had been against Dinamo Zagreb earlier this month - for the visit of little-known Astra in the Europa League on Thursday night. The 23-year-old player, though, dismissed suggestions that his team's subdued showing was a consequence of the number of spectators who filed through the turnstiles.

HE said: "The atmosphere wasn't a problem at all. I think the people who were there the other night started off very well of course because they want to get behind us.

"I think we let them down a little bit. More than a little bit. I would love to play in front of 60,000 crazy fans, but it's this way now. It doesn't affect us in any way."

Van Dijk has been frustrated by the inconsistency of Ronny Deila's charges this season and is keen for them to turn on the style against Kilmarnock in the league tomorrow.

He said: "We want to play great football - for the fans, but for ourselves as well. We want to make it easy for ourselves as well.

"We know that every home game in the Scottish Premiership our opponents are going to sit and wait until they can counter attack.

"We need to be sharp on the ball, keep the ball, create a lot of chances and score goals. That is what we're capable of and need to do.

"It has been a little bit inconsistent this season. We need to get a little bit of consistency in our play. But it takes a little bit of time. There were a lot of changes this season with past years. It takes time."

Meanwhile, the £2.3million signing, who was strongly touted for a move to the Barclays Premier League in the summer, has played down speculation linking him with Arsenal.

Van Dijk stressed that he is fully focused on helping Celtic climb the Premiership table, progress in the cup competitions and reach the last 32 of the Europa League.

He said: "Arsenal are an amazing club. It's a big club with a great history.

"But so are Celtic and I'm very happy here just now. I just want to play well and we will see what happens in the future.

"There are stories, but until there are bids or anything I can't say anything. I still have a contract and there is no bidding right now. The way it looks, I'll still be here.

"I have ambitions, but Celtic are an amazing club with a lot of history. There is no rush to leave, but you never know what will happen in the future."