Why Son Heung-min is not in Tottenham squad for game against Manchester United

Son Heung-min is set to miss Tottenham's Premier League clash with Manchester United at Old Trafford on Sunday.

The South Korean, who started in Spurs ' 3-0 Europa League victory over Qarabag on Thursday, was substituted after 71 minutes due to a hamstring concern.

This comes as a blow for the north London side ahead of their crucial match at Old Trafford. In his pre-match press conference on Friday, Spurs boss Ange Postecoglou revealed that while Son's condition wasn't "too bad ", and the player himself was keen to train on Saturday, it was unclear whether his issue was an actual injury or simply fatigue.

With doubts surrounding Son's availability for the Manchester United game, he South Korean star has not travelled with the squad to Manchester.

This could pave the way for Timo Werner to step into the attack, or potentially see Dejan Kulusevski shift from midfield to the front three, reports Football London .

Postecoglou also highlighted during his media interaction on Friday that Son's current playing time - totalling 549 minutes for the club and another 180 minutes across two international fixtures this season - is unsustainable.

"No," conceded the Australian. "I would have wanted to ease his workload this early part of the season, but we lost Richy and we lost Dominic [Solanke], then we lost Wilson [Odobert]. Sometimes, it's not the amount of injuries, but the kind of injuries you get. So he's played more than I think than I certainly want him to and the idea of signing Dom and bringing in Wilson and extending Timo [Werner's] loan was that we could manage his load because he's got international football as well."

"It's something that I'm mindful of but it's just the circumstances so far, and Sonny always wants to play, that's his attitude, but we've got to be sensible about it. I don't think it's got so much to do with his age because I haven't seen that affect him. It's more I just don't think that kind of workload in the modern game is sustainable. We've spoken a lot about fixture overload and part of that responsibility lies with us to try to protect our players and certainly with Sonny we're going to have to be mindful of that."

Postecoglou did go on to explain that Son will be left out of the team from time to time, although that is not a situation he will be discussing with Tottenham's No. 7.

"No. I tend not to make decisions by consensus," he stated. "I think when you've got a player like Sonny, I've had experience of working with guys like that before and they're always going to want to play. Do I want to dull that competitiveness by having a reasoned discussion with him over a cup of tea and saying 'Sonny, this is going to be great for you, great for me'?

"No, I'd rather I leave him out and he's disappointed with me because I think that's what you want in him, and sometimes it's doing something for someone's own good and that's my decision, my responsibility and I've got to take that on board."