The 21-year-old winger left Old Trafford for Chelsea last summer in a £40 million deal after falling out of favour under then-head coach Ruben Amorim, but has since struggled to establish himself at his new club.
Former United midfielder Nicky Butt, who previously worked at the club as head of academy from 2016 to 2019 and later as head of first-team development until 2021, branded Garnacho's attitude during his time at Old Trafford a "disgrace" and said selling him was the best decision the club could have made, adding that such behaviour would have been disciplined in his playing era.
Following the match, social media activity from several of Garnacho's former teammates appeared to echo Butt's sentiments and support his comments.
"The best thing for me that Manchester United did was sell him because, forget his ability, I don't think he's that great anyway," Butt told The Good, The Bad and The Football podcast.
"However, his attitude for me was a disgrace when he was at United.
"That's why that happens when people post things like that (Shaw on Instagram). If you are in a changing room and you leave and completely disrespect your team-mates and football club.
"Garnacho was always a bit standoffish. He had a high opinion of himself.
"I thought he had an edge about him and when he went into Manchester United's first team, and I will say what I think because I was there looking at it, he got above his station way too quick.
"He got a superstar status way too quick... but he got superstar status so quickly and then scored the bicycle-kick - which was a phenomenal goal - and then it went like that.
"Someone in that football club should have been swatting him down. They might have been and he's just ignored them."
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