The 28-year-old had been involved in one of the game’s key moments when he was adjudged to have been fouled by Scott McTominay in the build-up to the visitor’s first goal — scored by Edinson Cavani — which was then disallowed by a call made with the video assistant referee (VAR).
Son went on to score the opening goal of the game before United mounted its comeback, serving a major blow to Tottenham’s hopes of qualifying for the Champions League.
The South Korea international was subsequently targeted with racist messages on social media, with posts appearing on both Twitter and Instagram.
“Another matchday and more abhorrent racial abuse suffered by one of our players,” read a Tottenham statement posted on Twitter.
“This has again been reported to the platforms and we shall now undertake a full review alongside the Premier League to determine the most effective action moving forward. We stand with you, Sonny.”
Son has not yet publicly spoken about the abuse he received.
Social media companies have received widespread criticism for allowing footballers to continue being racially abused on their platforms.
Last month, former Arsenal striker Thierry Henry announced he would be boycotting social media until platforms found a way to tackle such abuse.
Swansea City has recently taken a step back from social media for a week to raise awareness of the issue which has become a regular occurrence. Rangers players and management have also boycotted their platforms for seven days.
Speaking to ITV on Thursday, Rangers player Glen Kamara said he has received racist abuse online “every day” since allegedly being racially abused in a Europa League game against Slavia Prague.
Twitter told CNN that it had taken action after the latest incident and removed a number of Tweets for policy violations.
“There is no room for racist abuse on Twitter and we are resolute in our commitment to ensure the football conversation on our service is safe for fans, players and everyone involved in the game,” said a Twitter spokesperson.
Facebook, which owns Instagram, told CNN that its teams were investigating the posts as a priority, and will provide and an update as soon as they can.
Son, who looked dejected after his side’s defeat, was heavily criticized by Manchester United manager Ole Gunnar Solskjaer for his role in the controversy surrounding Cavani’s disallowed goal.
Son went down clutching his face after McTominay appeared to have flicked him with his hand and Tottenham’s forward took a while to get back to his feet.
“If that was my son and he gets that from one of his mates and he stays down and he needs 10 other mates to help him up three minutes after, he’s not going to get food for a few days because that is embarrassing,” Solskjaer told BBC Sport after the match, adding he was “amazed and shocked” a foul was given.
Solskjaer’s comments didn’t go down well with Spurs boss Jose Mourinho.
“I just want to say, Sonny is very lucky that his father is a better person than Ole, because I think a father — I am a father — I think as a father you have always to feed your kids, it doesn’t matter what they do,” Mourinho said during his post-match press conference, criticizing the media present for not asking him about Solskjaer’s interview.
The loss means Tottenham loses ground in its bid to finish in the top four of the Premier League. It now sits six points adrift of the Champions League qualifying positions whilst United remains second in the table.