The Egyptian striker could make his first appearance with Ajax this term when they meet NAC Breda in the Dutch league on Saturday.
"I think he is fit to play," Ajax coach Martin Jol, who also managed Mido at Tottenham Hotspur, told a news conference.
"He could play 10 or 45 minutes, not more than that."
Mido, who made his name with Ajax in the early 2000s, has struggled with weight problems and groin complaint since moving to the 29-time Dutch champions on a season-long loan from English side Middlesbrough.
In-form duo Luis Suarez and Mounir El Hamdaoui are Jol's preferred partners upfront.
Uruguay World Cup striker Suarez and El Hamdaoui, who notched Morocco's winning goal over Tanzania in the African Cup of Nations qualifiers last weekend, have scored 12 goals between them so far this season.
Mido is trying to resurrect his career after disappointing spells with Middlesbrough, Wigan Athletic and his boyhood club Zamalek.
Ajax lie second in the league table with 17 points from eight games, just one behind leaders PSV Eindhoven.