The Moroccan midfielder was acquired on loan from Italian club Fiorentina on Friday evening, subject to international clearance and registration requirements.
Amrabat was ineligible for Sunday’s Premier League match at Arsenal and his shirt number will not be revealed until the move has been completed.
Ten Hag said he was “very pleased” to get the deal over the line and believes the 27-year-old will be a good addition to the squad.
In his post-match press conference at the Emirates Stadium, the boss explained: “It was already, from the start of the season, one of my wishes to get another [number] six, a holding midfielder, in the squad because through the season you need that depth there.