Anthony Martial and Jadon Sancho were among the Manchester United players to return for the first official day of pre-season training.
Tom Heaton, Aaron Wan-Bissaka, Raphael Varane and Fred also arrived at United's Carrington training complex on Thursday morning.
Amad and Hannibal Mejbri were back at United after season-long loans in the Championship with Sunderland and Birmingham City.
Amad, 20, excelled at the Stadium of Light, scoring 14 goals in 42 appearances as Sunderland reached the play-offs. United manager Erik ten Hag indicated in May that Amad would stay in the squad for the forthcoming season.
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Mejbri, also 20, faces an uncertain future at United and Borussia Dortmund are interested in the Tunisia international.
Rookies Charlie Savage, Maxi Oyedele and Isak Hansen-Aaroen could be involved in training this week amid the absence of several first-team squad members.
Dean Henderson, Lisandro Martinez, Donny van de Beek, Kobbie Mainoo and Antony have been at United's training base over the last week to continue their rehabilitation from long-term injuries.
Van de Beek has not played since January due to a knee injury, Henderson had thigh surgery in May, Martinez fractured a metatarsal in April, Antony sustained an ankle injury in United's penultimate Premier League game against Chelsea last season and Mainoo missed the run-in.
Martial missed the FA Cup final with a hamstring tear but he could be fit for the start of United's seven-game pre-season schedule.
United players who were involved in internationals last month are not due to report for pre-season training until later this month.
Harry Maguire, Luke Shaw, Marcus Rashford, Bruno Fernandes, Diogo Dalot, Victor Lindelof, Anthony Elanga, Casemiro, Christian Eriksen, Scott McTominay, Alejandro Garnacho, Tyrell Malacia, Facundo Pellistri, Alex Telles and Eric Bailly were all on international duty in June.
United play their first pre-season friendly against Leeds United in Oslo on Wednesday and take on Lyon in Edinburgh before travelling to the United States for their tour.
The first team will play against Arsenal, Real Madrid and Borussia Dortmund in the States while the academy will face Wrexham.
United will then play two friendlies in successive days against Lens at Old Trafford and Athletic Bilbao in Dublin a week before the Premier League season commences.
