Former Manchester United winger Angel di Maria believes manager Louis van Gaal was to blame for his failure to live up to his potential at Old Trafford.
Argentina international Di Maria joined the Red Devils from Real Madrid in the summer of 2014 for a then-British record fee of £59.7 million ($75m).
But he struggled to perform on a consistent basis, contributing four goals and 12 assists in 32 appearances before departing for Paris Saint-Germain at the end of the 2014-15 campaign.
Di Maria, though, believes he could have offered so much more had Van Gaal, who was regularly criticised for his negative brand of football, allowed him to express himself further.
"I only stayed for one year. It was not the best time of my career, or rather I was not allowed to spend my best time there," he told France Bleu.
"There were complications with the coach at the time.
"But thank God, I was able to come to PSG and demonstrate again who I was."
Di Maria will return to Old Trafford with his PSG team-mates when the two sides meet in the last 16 of the Champions League.
Despite being 13 points clear at the top of Ligue 1 and well on track to win a sixth French title in seven years, the Parc des Princes outfit have struggled to lay down a marker when it comes to their European performances.
But, having come through a tough group containing Liverpool and Napoli, there is hope that Thomas Tuchel's side have what it takes to challenge in Europe's premier club competition.
Di Maria, however, is wary of Man Utd's upturn in form under Ole Gunnar Solskjaer, with the Norwegian interim manager winning all six of his matches in charge since replacing Jose Mourinho on the touchline.
"We still have matches before facing Manchester," he added. "They have changed with their new coach and they have not lost a match.
"I think we started the year not so well in the Champions League, but we put the situation right and we finished top of the group.
"It was complicated. Ever since the draw it was said that it would be difficult to reach the round of 16 and we were almost eliminated, but we played a big home game against Liverpool and also against Red Star Belgrade - two big, decisive matches to qualify.
"Now, we must think of ourselves and nothing but ourselves. If we do things well, everything will be fine."