Mitroglou moved to Craven Cottage on transfer deadline day from Olympiacos, but has yet to feature for the Premier League strugglers due to a lack of fitness.
The striker's only appearance in a Fulham shirt came for the club's under-21 side on Wednesday as he scored twice in a 5-3 defeat to Aston Villa.
The 25-year-old, Fulham's club-record signing, scored 14 goals in the Greek Super League in the first half of this season and Meulensteen is keen to get him involved in the first team as soon as possible.
"We are working hard to get him (Mitroglou) fit and up to speed," the Dutchman said after Wednesday's 3-2 defeat to Liverpool.
"That's why we thought it was a good exercise to get him some playing minutes for the under-21s.
"It worked well for him."
Fulham sit bottom of the Premier League, four points from safety, but Meulensteen is confident the new players he brought into the club in January are slowly making a difference.
"You can see there is definitely improvement," he added. "The new players are making a difference within that."
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