Martin Jol blamed his 'immature' strikeforce for Tottenham's shock 1-0 Carling Cup defeat to League Two leaders Grimsby.
Jean-Paul Kamudimba Kalala struck a sensational late winner for the Lincolnshire minnows as they overcome a Spurs side containing five England players in their starting line-up.
Russell Slade's men produced a display of sheer guts and determination to overcome Tottenham's galaxy of multi-million pound talent.
But, as Jol acknowledged, Tottenham strike pairing Robbie Keane and Jermain Defoe were so ineffective it came as little surprise Grimsby were able to grind out a memorable victory.
'We aren't scoring goals, and we don't look like scoring goals, which is even worse and is not good enough,' said Jol, whose side have now scored just once in their last five games.
'You know that if they get a free-kick or a corner that they can score and that's what happened.
'But we knew that beforehand and you have to make the difference up front. Sometimes we looked a bit immature.
'The best player, overall, was Aaron Lennon when he came on - and he's 18 years old.
'If you play against big players like they have, then you need to move quick and use your extra mobility.'
With Egypt striker Mido suspended and new signing Grzegorz Rasiak cup-tied, Keane was restored to the starting line-up for only the second time this term to spearhead Tottenham's attack alongside Defoe.
But the pair struggled to make any impact and their lack of productivity had Jol repeating his complaint about the duo not being compatible as a strike partnership.
'If you have two small strikers against two big centre-backs, then you need to move to cause them problems,' added Jol.
'But if you don't move then you don't cause them any problems and that's exactly what we did.
'If you don't score then it's always going to be a problem and then they punished us.
'If you play Keane and Defoe then you struggle for the physical side, but if you work like you should do then it shouldn't be a problem.
'But it is and this has been my story all along, and why I like to play a big man with a little man working off him.'
Grimsby boss Slade heaped lavish praise on his players after their spirited display, but was reluctant to single out Kamudimba Kalala.
The Congolese midfielder, who arrived from Nice on a free transfer during the summer, produced an excellent long-range strike to bundle the Barclays Premiership giants out the competition.
Slade said: 'We had a gameplan to unsettle Spurs and we knew that we could get at them from set-plays.
'I thought we gave them a run for their money all night and obviously when the goal went in it made life very difficult for Spurs.
'I think it would be unfair to single any one player out, because there were many, many man-of-the-match performances out there.'