The Argentine defender was reportedly frustrated that Manchester United had to use the young centre-back out of position after Luke Shaw’s injury during Tuesday’s 2-0 Champions League defeat in Madrid.
According to The Sun, Martínez believed the decision highlighted a lack of defensive cover and reflected badly on the club’s summer recruitment. The report said his criticism was directed at the club’s hierarchy rather than Heaven himself.
Martínez publicly questioned the backing provided to head coach Michael Carrick and singled out director of football Jason Wilcox after the defeat. The comments prompted discussions with the club’s leadership, followed by an apology on Thursday.
The reported disagreement over Heaven’s role centres on United’s need for a natural alternative at left-back when Shaw is unavailable. Heaven is primarily a centre-back, and using him in a different position against Atlético brought the squad’s defensive options into focus.
The report also claimed Carrick had wanted Newcastle United’s Lewis Hall as cover for Shaw during the summer, but that the move did not happen. United instead invested heavily in midfield, leaving questions about the balance of their recruitment.
A source said: “Martinez was furious because he thinks having to play Ayden at left back away in Madrid shows how ill-equipped the squad is. It doesn’t have enough depth.
“And the fault of that lies squarely with the board.”
Martínez met with Manchester United’s leadership and Carrick on Thursday and apologised for his remarks. The club has not publicly confirmed whether the defender was fined, despite reports suggesting disciplinary action may have been taken.
The episode comes during a difficult start to the season for United, with the Atlético defeat adding to pressure on Carrick and the club’s football leadership. The team’s defensive depth and the extent of its summer recruitment are now part of a wider debate about how United can compete consistently in domestic and European football.
A planned team meal was also reportedly cancelled after the defeat, adding to the sense of frustration within the squad. United were due to travel to Leeds for their next Premier League fixture on Sunday.
For Martínez, the dispute has exposed a tension between the demands of a senior player who wants the club to strengthen and the responsibility to maintain confidence among the younger players already in the squad.