The worry for Virgil van Dijk is obvious. Holland’s national team have already conceded more goals in five Euro 2016 qualifiers than they lost in the entire qualifying campaign for the last World Cup. And still Guus Hiddink never calls or writes. The Celtic defender made it into two squads last year. But one step forward is usually followed by two steps back. When the Dutch were drawing 1-1 with Turkey the other night he was sunning himself in the Arabian Gulf and bumping into club-mates instead. Virgil van Dijk has been in fine form for Celtic but wasn't rewarded with a call-up to the Holland national team . Van Dijk's last call-up to the Dutch side came last year though he has never been capped by his country . ‘I saw Stuart Armstrong and Callum McGregor,’ he says in deadpan fashion. ‘The better players were with their national teams. I was in Dubai.’ A holiday in Dubai is rarely a cause of self-pity. Yet van Dijk’s gripe is obvious. His breakthrough to the national squad was short-lived and he can’t shake the nagging belief that he might have a better chance of playing for his country if he performed in a more respected league than the SPFL. Celtic boss Ronny Deila denies this, using Jason Denayer’s Belgium debut against Israel by way of a counter argument. ‘I don’t think the Belgian national team is any worse than the Dutch,’ he insists. ‘Right now, it is better. So I don’t think that is the answer. ‘I don’t know the level of the other central defenders in Holland, but they must be very, very good to be better than Virgil, in my opinion.’ Van Dijk’s rivals for Hiddink’s attentions are Stefan de Vrij, Bruno Martins Indi, Jeffrey Bruma and Joel Veltman. None are superstars. But they play in Italy, Portugal or Holland. All three leagues have a better reputation than the SPFL and the worry for Celtic is that van Dijk knows it. Van Dijk says he was happy for team-mate Jason Denayer,  who made his debut for Belgium against Israel . ‘Yes, I think that’s maybe one of the big reasons,’ says the defender. ‘They don’t take the (Scottish) league too serious. I don’t know what the reason is, but until then I just need to keep working and hopefully get a call-up. ‘Nobody asks the manager (Hiddink) or his staff either why I’m not getting a call-up. For me, the only thing I can do is play well for Celtic, work hard and prove myself day in and day out. ‘I’ve watched most of the games, including the highlights from the Turkey game last week. Sometimes you hope you get a chance. But until that day will come, it’s just for me to work hard and win games for Celtic and prove myself. ‘If I’m in the national team it would be a big bonus because it’s only like last season that I’ve been playing okay and I’ve tried to continue that this season. If I get a call-up then great.’ Through any disappointment he could find a silver lining in being overlooked once more. ‘It was a little bit disappointing when the squad was announced,’ he concedes. ‘But the day I knew I was getting a week off was a better day, I think. ‘My feeling is I needed this break a lot. I’ve never played so many games in a season as I have this year so far and the travelling is also quite hard at time, mentally. ‘I needed a nice break with the family away to get some rest and to be ready for Friday. I’ve been to Dubai and got some nice sun and relaxation.’ Ronny Deila believes the standard of Scottish football makes no difference to Holland's decision-making . There is no envy of his friend and defensive partner Jason Denayer. The 20-year-old was called into the fray for Belgium after Vincent Kompany was sent off in midweek, playing half an hour for his homeland. ‘I’m very happy for him,’ insists van Dijk. ‘He is a good friend of mine now and I’m very happy he made his debut. It was a good day for him.’ Whether either player will still be at Celtic next season is impossible to say. Van Dijk plays questions with a straight bat. As all footballers must, he insists he thinks little of transfer matters so long as there are trophies to play for. ‘I speak to my agent almost daily,’ he reveals. ‘But he’s more than an agent to me, he’s also become a very good friend. ‘He knows exactly what I want and what I don’t want to hear. So, we have a very good relationship and that remains that way. ‘I don’t think about all that at the moment, not at all. I think about the Treble. ‘We have one cup now and the other two are close, so I want to win both of them and write some history. That’s all I’m thinking about. I’m not thinking about this is going to be my last season at the club or anything else.’ Van Dijk leaves the field after being sent off against Inter Milan in the Europa League in February . Like van Dijk, his coach Deila also took a holiday ahead of Friday night’s clash with St Mirren in Paisley and the final stretch of the domestic season. ‘I was in Marbella for a week, 25 degrees in the sun,’ says the Norwegian. ‘So that was good. I needed that. ‘I switched off. It was a good week. Of course you are always thinking a little bit and watching the international teams, what’s happening there, but it was a very, very good week. ‘I’m ready now and looking forward to Friday. ‘It’s our possibility to take some days off - because during the season you play three times a week so there’s never a chance to do anything. When we have international team breaks, we have 70 per cent of the squad away on duty. It’s good to use those periods.’
Virgil van Dijk was on holiday in Dubai while Holland played two games .
Young Celtic defender hasn't been called up since last year .
Ronny Deila says it isn't due to standard of Scottish football .
Team-mate Jason Denayer made his Belgium debut against Israel .