Tottenham midfielder Dele Alli questioned the mentality of his side after crumbling to a 3-0 Champions League last 16, second leg defeat to Leipzig on Tuesday to bow out of the competition 4-0 on aggregate.
Marcel Sabitzer profited from two errors by Spurs goalkeeper Hugo Lloris in the first 21 minutes to give Leipzig a commanding lead before substitute Emil Forsberg added the third late on.
Tottenham manager Jose Mourinho was repeatedly used the absence of key injured players such as Harry Kane and Son Heung-min for a run of six games without a win in all competitions.
But Alli insisted that is not a good enough excuse for the manner in which last season's Champions League finalists exited the competition with a whimper.
"We were missing some good players, but that's football, that happens. This is Tottenham, the players that come in have to step up and we haven't done that today," Alli told BT Sport.
"I think we have to apologise to the fans. They travelled all this way and to go out and lose like that, they deserve better."
Alli refused to point the finger at Lloris, but claimed Spurs were not mentally strong enough to produce the same sort of fightback as they did from 3-0 down on aggregate against Ajax in last season's semi-finals.
"We were second to a lot of balls, to concede them goals shows our mentality wasn't strong enough," added Alli.
"We have to stay together and not talk about anyone in particular.
"It's not down to one player to score goals, to stop goals, the whole team performance and the mentality wasn't strong enough."
Tottenham now have just nine games left this season in the Premier League to try and avoid missing out on the Champions League for the first time in five seasons.
Mourinho's men lie eighth in the table, seven points off the top four, and badly need to end their barren run at home to Manchester United on Sunday.
"I think probably it is (a) good (thing)," said Mourinho of his side's exit from Europe. "Sometimes difficult moments are moments that can prepare the future in a better way."
On top of losing Kane and Son, Mourinho pointed to the absence of Steven Bergwijn, Moussa Sissoko and Davinson Sanchez for his side's capitulation in Germany.
"People can say excuses but I'm pretty sure it is bad for anyone.
"I don't think anyone would resist to such a situation. In this moment we have matches to play in the Premier League with these players, there are not others, and we go until our limits. Let's see how we end the season."