Son Heung-Min was not named among the Tottenham squad to face Manchester United in the Premier League on Sunday after he picked up an injury in Spurs' midweek victory over Qarabag.
The Spurs captain limped off the pitch after receiving treatment in the 71st minute of Thursday's Europa League match in north London, with Ange Postecoglou saying that Son was suffering with "fatigue in his hamstring" in his news conference on Friday.
"Short turnaround [for Son], he just wasn't right for today so we go in without him," Postecoglou told Sky Sports on Sunday.
"We've had those things a fair bit. We just have to learn to cope without [him]. Timo [Werner] is most comfortable in that position. We brought him into the club for situations like this.
"Facing a big club, iconic stadium, plenty of attention -- these are the kind of games you want to be involved in. We won the last three. Results have been mixed but performances haven't been too bad. I'm pretty happy with how we're playing our football."
Son has featured in every game for Spurs this season, including the Carabao Cup third-round win over Coventry City on Sep. 18, and Postecoglou said that the 32-year-old cannot play in such a high percentage of Tottenham's fixtures this season moving forwards.
Asked whether it is "sustainable" for Son to continue playing so many minutes for Spurs at the age of 32, Postecoglou said: "No, no ... I would have wanted to ease his sort of workload in this early part of the year. But we lost [due to injury] Richy [Richarlison], then we lost Dominic [Solanke], then we lost Wilson [Odobert]. Invariably in football sometimes it's not the amount of injuries, it's the kind of injuries you get. So, he's played more than I think I certainly want him to."
On Wednesday, Son spoke out against the volume of games that elite footballers are now being asked to play, saying that it is "sometimes very hard" and that "the risk of injury is massive."
United manager Erik ten Hag, meanwhile, gave summer recruit Manuel Ugarte his first Premier League start in midfield, but defender Harry Maguire was missed out after reportedly picking up a knock in training.