Roberto Martinez has hailed the impact of the newcomers in his Belgium squad but is set to stick with the senior players who guided the country to third place at the World Cup for the forthcoming matches against Scotland and Iceland.
The Red Devils are in friendly action in Glasgow on Friday before playing their opening Nations League game in Reykjavik.
Christian Benteke, Marouane Fellaini and Simon Mignolet have all withdrawn from the squad through injury but uncapped quartet Timothy Castagne, Leandro Trossard, Hans Vanaken and Birger Verstraete have made their presence felt in training.
"They were awesome," Martinez told reporters. "They worked hard and earned the right to be part of this group. They made a good impression on me.
"I do not yet know my team for against Scotland, there is still a training [session] but this match is a preparation for the one in Iceland.
"This is the first time we meet after the World Cup. We do not have the time to make 11 changes. We'll have a team as strong as possible in both games."
Dries Mertens spoke alongside his coach and the Napoli forward expects to enjoy the extra scrutiny a World Cup bronze medal is likely to bring.
"I like that," he said. "It's important for us to see how our opponents are viewing us.
"Now you have to be professional, otherwise it's dangerous. We're hungry to continue what we did in the World Cup.
"It starts on Friday, it's very important not to let go."
All three of Mertens' appearances in Serie A have been from the bench this season – something the 31-year-old confirmed was pre-planned with club boss Carlo Ancelotti following his late return from Russia 2018.
"I talked to the coach, the intention is to make me play more in the future," he added.
