Based on recent reports and expert opinions, three players that Manchester United should not sell this summer, apart from the previously mentioned Kobbie Mainoo, Alejandro Garnacho, and Rasmus Hojlund, are:
Marcus Rashford: Despite the rumors linking Rashford with a move away from Old Trafford, it would be unwise for Manchester United to let go of their talented academy graduate. Rashford's pace, skill, and versatility make him a valuable asset to the team, and his commitment to the club should not be underestimated.
Bruno Fernandes: The Portuguese midfielder has been a key player for Manchester United since his arrival in 2020, contributing goals and creativity from midfield. Selling Fernandes would weaken the team's attacking options and could disrupt the balance of the squad.
Casemiro: The experienced Brazilian midfielder has brought stability and leadership to the team since his arrival from Real Madrid. Casemiro's defensive prowess and ability to control the midfield are essential to Manchester United's success, and the club should prioritize retaining his services.
These three players have proven their worth to Manchester United and should be considered integral to the team's future success. Selling them would likely weaken the squad and make it more challenging to compete at the highest level.