Manchester United are reportedly concerned about the strain being placed on Bruno Fernandes.
The 26-year-old has been in impressive form for the Red Devils since arriving in January, scoring 14 times and contributing 10 assists in 26 appearances in all competitions.
The Portuguese's form towards the end of last season was a key contributor to United claiming a top-four finish in the Premier League, and he has also been in good form at the start of 2020-21, scoring twice and providing two assists in four outings.
According to O Jogo, though, the Red Devils are worried about the mental and physical strain being placed on the playmaker, who has taken on a leadership role for the club since his arrival.
The report claims that the demands on the former Sporting Lisbon playmaker played a role in Ole Gunnar Solskjaer's side undertaking a busy transfer deadline day, which saw deals for Edinson Cavani, Alex Telles, Amad Diallo and Facundo Pellistri go through.
Fernandes is currently with the Portugal squad preparing for their upcoming internationals against Spain, France and Sweden.