Kevin Magnussen will sit out a number of Friday practice sessions in the second half of 2017 due to contractual details.
"The reason Kevin is missing more than Romain [Grosjean] is merely because of our agreements," Haas chief Gunther Steiner told Ekstra Bladet.
"Romain's contract was done in the summer of 2015, and Kevin's in autumn 2016.
"Kevin understood this from the very beginning and has shown a willingness to put the team first ever since he started with us."
Haas have picked up 14 points so far in 2017.