But Leto, a £2million signing from Lanus at the end of last season, will be included in boss Rafael Benitez's squad when Liverpool fly to Holland on Friday morning.
Benitez said: "He (Leto) will be able to play in Holland. Leto will travel with the squad and we have permission to play him in these games.
"It's good news for him because it's not easy when you're only training. You want to play in the games."