25-year-old Roerslev, who has revived his relationship with Riemer at the Danish national team after the former Anderlecht-boss worked as assistant coach at Brentford, made his debut in a match against Serbia in the autumn.
In addition to Roerslev, Riemer will be without the services of Benfica's right-back Alexander Bah, Pierre Emile Hojbjerg and Kasper Dolberg who are all nursing injuries.
Victor Nelsson has long been a regular part of the Danish national team and was also part of the most recent national team game against Serbia in November.
But the defender has not been granted much playing time since moving from Galatasaray to Roma on a loan deal in January.
He has only been in action three times in the Serie A, while he has had a single appearance in the Italian cup tournament.
Denmark will face Portugal on Thursday in the Nations League quarter-final.