Mauricio Pochettino accused his Tottenham players of failing to "respect the plan" in their Champions League draw with Olympiacos.
Having led 2-0 after half an hour in Athens, Spurs were pegged back to draw 2-2, allowing Bayern Munich to move top of Group B with a 3-0 win over Red Star Belgrade.
Harry Kane opened the scoring with a penalty 26 minutes in, which was the visitors' first shot of a match in which they were second best.
Lucas Moura struck a fine second but Daniel Podence halved the deficit just before the interval and Mathieu Valbuena's second-half penalty sealed a point for the Greek side.
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Pochettino was unhappy with Spurs' display throughout the contest and felt they did not show anywhere near the level of effort they produced in last Saturday's 4-0 Premier League win over Crystal Palace.
"I feel very disappointed. To be honest, first half, I wasn't happy with our performance," he said.
"From the beginning, we had a plan. We didn't respect the plan. I told the players at half-time.
"We scored two goals but if you only analyse the performance, it wasn't great. We conceded a lot of chances to them and the first goal was so painful. We didn't translate that type of aggression these types of games demand.
"How many times didn't we anticipate? And how were we not proactive like we were against Crystal Palace? At this level, you need to match your opponent. That is the first demand."
Spurs, who travel to Leicester City in the league this weekend, host Bayern on matchday two on October 1 and Pochettino wants his players to be optimistic about improving on Wednesday's result.
"It's disappointing because we are not talking about quality, we are talking about intensity, will and aggression," he told Spurs TV.
"We need to be optimistic and positive. It's only the beginning, a point here and now we need to be ready for Saturday when we play Leicester and that's going to be another tough game."
2 - Tottenham failed to win a Champions League game having been two goals ahead for the second time and first since drawing 2-2 with Werder Bremen in September 2010. Pegged. pic.twitter.com/fMO0SnG3Fw
— OptaJoe (@OptaJoe) September 18, 2019
