Belgium boss Marc Wilmots recently claimed that the Manchester United starlet has pledged his international future to the country of his birth, prompting speculation that he could make the trip to Brazil in June.
However, with the 19-year-old having been used sparingly for United in recent months, Mirallas feels that there are sharper options for Wilmots to select for his 23-man squad.
He told Belgian television station RTBF: "First of all, I am happy for Januzaj that he has finally taken a decision, as there was a lot of pressure on him.
"It's good for Belgium as he is a good player. Now, as a lot of people have already said, maybe he doesn't deserve to go to Brazil as he doesn't know the group at all and he hasn't played many games at Manchester United.
"In the last few months, he hasn't played much. But why should we leave a good player at home? In his positions, we have a lot of players and it will be difficult for him. He still has to prove at his club that he is a first choice. For him, Euro 2016 is a better objective."
Januzaj has scored four times in 24 Premier League appearances for the Red Devils this season.