Nacer Chadli takes a deep breath and for a fleeting moment stares vacantly into the distance. The Tottenham Hotspur and Belgium midfielder is discussing his father’s passing in January when he pauses to consider how difficult it was to return to football after the funeral in Morocco. It hit him hard but when his performance levels, after an impressive start to the season, dropped ever so slightly during that period of mourning there was no shortage of criticism.

A sign of the times and the overburdening level of expectancy bestowed on players, perhaps, but Chadli continued to battle. The 25-year-old’s steely resolve shone through. Jibes from pundits after a stray pass here or a mistimed tackle there were not going to derail him.

“It was difficult going back for the funeral but important to be with my family during that time,” Chadli says. “I needed to be there to support them and I needed them to support me through it. But after a few days I was ready to go back. When you’re mourning, I think it’s important to focus on doing something that you love to help you and to get me through it I had football.”

Spurs wore black armbands in the first leg of the Capital One Cup semi-final against Sheffield United as a mark of respect. “I was touched by how the club and my team-mates dealt with it,” Chadli says. “They were excellent during a difficult period and it was very welcome by my family.”

Now he is back on international duty for the first time since suffering that loss. Having grown up in Liège, a stone’s throw from one of his best friends and international team-mate Axel Witsel, Chadli had always wanted to turn out for Belgium, but when Morocco, his father’s birthplace, approached him in late 2010 he explored.

He was man of the match in his only Morocco appearance, a friendly against Northern Ireland at Windsor Park, before George Leekens, the Belgium manager at the time, came calling a few weeks later.

“I was going to choose Morocco but the [Belgium] manager invited me to come visit the group and see how I feel,” he says. “I didn’t want to rush the decision – if I joined I didn’t want to regret it – but I went for a look and was 100% certain I wanted to play for Belgium. I still love Morocco but there was something there I wasn’t sure with so thought about it and changed.

“There was some pressure from Morocco for me to commit but with Belgium there was no real pressure and it felt like the right thing to do.”

He has not looked back. The not-so-dark horses of last summer’s World Cup will be among the favourites at Euro 2016. In Group B, which also includes Wales, Marc Wilmots’ team are there to be shot down and the other sides are intent on doing so.

“The favourites tag is something we’re still trying to come to terms with,” Chadli says. “Even three or four years ago we were a small country that nobody really cared about. Now everybody knows about our squad and we’re no longer underestimated.

“We should have even more young talent coming through, also. The under-19s and under-21s have some very good players. It’s very much about the structure but there is also some luck because we’ve had so many great players come through at once.”

Chadli, who joined Tottenham from the Dutch club Twente in 2013, had a mixed first season at White Hart Lane and he was regularly linked with a move away, including repeatedly to Swansea before Gylfi Sigurdsson made the trip from north London to south Wales instead. But on returning at the start of this season under new management, he was fitter, faster and stronger, instantly making himself an integral part of Mauricio Pochettino’s plans.

He had a 20-day turnaround between Belgium’s World Cup elimination by Argentina and the start of pre-season. And even then he needed to play catch-up as most of Spurs’ squad were already being put through the rigours of Pochettino’s notorious fitness regime.

He credits a trip to Henri Chenot’s Palace Merano, a health facility in a secluded part of northern Italy, for preparing him, despite conceding “it wasn’t until I got back to the club that I heard about the manager’s focus on fitness”. Chadli lost several kilos, was given in-depth dietary advice and, as a result he says, started the season in the shape of his life.

“It’s better for you to eat fruit before a meal instead of after because of the fibre,” he says, outlining one piece of knowledge and advice he was given in Merano.

Dairy was also knocked on its head but, amusingly, he is describing all of this with a slice of pizza in hand. “Cheat day,” he tweets after we meet in an east London bar, but the subtle lifestyle change is, to borrow a phrase from cycling, geared towards giving him a marginal gain. “You always want to get that extra 1% improvement and you need to take care of your body more.

“Even if you look 10 years back and the difference between now. There are so many additional products to help you, like the various protein shakes. And treatment like in Italy is important because it gives me that little bit more.

“In another 10 or 15 years, there’s going to be even more emphasis because we’ll be playing more games. You’re going to have players who will play 70 or 80 games because of the treatments available and the ability to recover faster.”

Rest is the last thing he wants at present, though. Cyprus on Saturday and Israel on Tuesday need to be beaten after two draws from their opening three qualifying games. “We’re stronger now than before,” he says of the Belgium squad. “We’re aware of our quality but we also know we can improve a lot. Starting with these games.”