Werner, 28, was replaced by Dejan Kulusevski at half-time of the Europa League tie at Ibrox, which extended Spurs' winless run to five matches in all competitions.
Kulusevski scored a 75th-minute equaliser, cancelling out Hamza Igamane’s goal at the start of the second half, to rescue a point for injury-hit Spurs, who started with 18-year-old Archie Gray as an auxiliary centre-half and introduced another teenager, Lucas Bergvall, on the hour.
Postecoglou, the former Celtic boss, was left furious at Werner’s display and revealed he had given the Germany international a dressing down.
“He wasn’t playing anywhere near the level he should,” said Postecoglou after confirming that he had replaced Werner for tactical reasons.
“When you’ve got 18-year-olds \[playing\], it’s not acceptable to me. I said that to Timo.
“He’s a senior international, he’s a German international.
“In the moment we’re in right now, it’s not like we’ve got many options. I need everyone to at least be going out there trying to give the best of themselves. His performance in the first half wasn’t acceptable.”
Asked how Werner took the dressing down, the Spurs head coach said: “Don’t really know. It’s not really of great concern. We need everybody including him to be contributing.
“Because we don’t have the depth to leave people out if they’re performing poorly.
“We need them to play their part. Especially the senior guys. When I’m asking younger guys to do massive jobs. I expect a level of performance from some of the senior guys. And today wasn’t that.”
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