The Amsterdam club have named a 17-man travelling party for the match in Denmark, but star players Andre Onana, Dusan Tadic, Davy Klaassen and Ryan Gravenberch are conspicuous by their absence.
The quartet are important starters, with Tadic outstanding during the club's run to the final less than 18 months ago and Gravenberch having emerged as one of Europe's rising stars in the heart of the midfield.
Reports in De Telegraaf state that there has been a significant outbreak of Covid-19 in the squad, leaving 20-year-old Kjell Scherpen, who has not played a first-team game for the 2019 finalists, the only goalkeeper to travel.
Nevertheless, eight of the starting players who were in the team that defeated Fortuna Sittard 5-2 on Saturday are present, while of the substitutes that day only Maarten Stekelenburg and Promes drop out for this clash.
The double header against the Danish champions promises to be pivotal in their qualification hopes.
Ajax suffered a 1-0 home loss to Liverpool in the opening round of fixtures then failed to hold onto a 2-0 lead in Atalanta, ultimately drawing the match 2-2.
Consequently, they are left on a single point after two games, with successive matches against the side fancied as the pool whipping boys to follow.
Midtjylland suffered a 4-0 rout at home to the Serie A side in matchday one, and though they improved in a 2-0 loss against Liverpool at Anfield last week, they remain dramatic outsiders to progress.
However, Brian Priske’s side, who are in their debut Champions League campaign, stand a far stronger chance of defeating a depleted Ajax team, which is exactly what Erik ten Hag will be travelling with.
Ten Hag will address the press on Monday evening, when he will likely offer an update on the status of the vast number of players he will be without.
Kjell Scherpen; Perr Schuurs, Noussair Mazraoui, Daley Blind, Lisandro Martinez, Nicolas Tagliafico, Sean Klaiber, Jurrien Timber; Edson Alvarez, Jurgen Ekkelenkamp; David Neres, Antony, Quincy Promes, Lassina Traore, Klaas-Jan Huntelaar, Brian Brobbey, Victor Jensen