The Reds face a demanding schedule of nine matches in 28 days, with injuries further limiting their options.
"You don’t have a lot of time to train," Iraola told the media.
"You try to prepare the games now a lot of times just with the videos and the tactics boards, just a little bit outside.
"You have to prioritise the freshness of the players. Especially now we are playing four games in ten days, it’s keeping all the legs, all the energy in the games."
Dominik Szoboszlai misses out with a hamstring problem, while Alexander Isak and Cody Gakpo remain sidelined.
Federico Chiesa and Wataru Endo are also unavailable after being omitted from Liverpool’s European squad.
Youngsters Trey Nyoni and Lewis Koumas feature alongside Ryan Gravenberch and summer signing Bradley Barcola as Liverpool chase consecutive European victories.