GLASGOW, Scotland -- Tottenham Hotspur head coach Ange Postecoglou gave a scathing assessment of Timo Werner's performance in the team's 1-1 Europa League draw with Rangers on Thursday, saying the forward's performance "wasn't acceptable."

Werner, who is playing in his second season on loan at Spurs from RB Leipzig, was replaced by Dejan Kulusevski after enduring a difficult first half at Ibrox.

Asked if the substitution was made for purely tactical reasons, Postecoglou said: "Yeah, he wasn't paying anywhere near the level he should."

Spurs conceded within two minutes of Kulusevski's introduction, but the Sweden international went on to score his team's equaliser.

"I think Rangers played very well. We struggled a bit. 1-1, it is what it is. We didn't play well enough to win the game," Kulusevski said after the match. "It's always important to score, but we've got to start winning games.

"We haven't won in a couple of weeks. Everybody needs to do a little bit more than we're doing right now."

Postecoglou also referenced the performances of two Spurs 18-year-olds -- Lucas Bergvall and Archie Gray.

In the injury-enforced absence of Spurs' senior defenders -- Cristain Romero, Micky van de Ven and Ben Davies -- Gray filled in at centre-back in Glasgow and drew glowing praise from his manager who described him as "outstanding."

Bergvall was introduced as part of a 75th-minute triple substitution that proved pivotal in helping Spurs earn a vital point from their trip to Scotland.

Postecoglou, who has seen his role as Spurs head coach come under serious pressure after a succession of disappointing results in recent weeks, pointed to the impact made by the teenagers when asked if he needed Werner and other senior players to make a bigger contribution to the team.

"I think when you've got 18-year-olds, I think it's not acceptable to me. I said that to Timo, he's a senior international, a Germany international. In the moment we're in right now, it's not like we've got many, kind of, 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 what he put Werner's performance down to, Postecoglou said: "I don't really know. It's not really of great concern. Like I said, we just need everybody, including him, to be contributing because we don't have the depth to sort of leave people out if they're performing poorly, we need them to play their part.

"And like I said, especially the senior guys, when I'm asking younger guys to do massive jobs, I expect the level of performance from some of the senior guys and today wasn't that."

The draw at Ibrox saw Spurs remain ninth in the Europa League table, one place below Rangers, who occupy the last automatic qualification spot for the knockout rounds.