The runaway Spanish league leaders succumbed 3-1 in the second leg at the Camp Nou on Tuesday night to lose 4-2 on aggregate and relinquish their grip on the trophy they claimed by beating Athletic Bilbao in the 2012 final.
And former Real Madrid manager Toshack says he was unimpressed by a host of Barca players, both against Real and in last week's Champions League defeat to AC Milan.
"This seems a ridiculous thing to say with the La Liga Championship sewn up (Barcelona are 12 points ahead of Atletico Madrid and 16 ahead of Real), but there are a lot of worrying signs for Barcelona," Toshack told Sky Sports HD.
"Lionel Messi said he was happy playing with David Villa before the Clasico but the interim coach (Jordi Roura) left the latter out of the starting line-up, Xavi and Sergio Busquets did not show up in the game, and (Cesc) Fabregas looks unhappy.
"They didn't muster a shot on goal in the San Siro and they looked like they could play all night against Real and not score, while they can get frustrated when they come up against organised players.
"This is Real Madrid and not, with the greatest respect Real Zaragoza or Real Murcia, and while the Milan team is not the greatest of all time it is not chicken fodder either - but Barcelona have shown a lack of desire over the last seven days."
Spanish football pundit Guillem Balague, meanwhile, believes Barca's problems were evident last season, when they finished second to Real in La Liga and were knocked out of the Champions League in the last four by Chelsea.
And the Revista regular says one of the primary reasons Pep Guardiola - who will take over German giants Bayern Munich in July - left the Camp Nou dugout last summer was because he no longer thought he could get the best out of the squad.
"Pep felt he couldn't change his message and realised that whatever he said there were little bits that weren't right," said Balague. "And in both the Champions League against Chelsea and La Liga against Real Madrid, Barcelona made individual and collective mistakes.
"Guardiola thought he had better leave and get (Tito Vilanova) in to talk to the players; he could see what he believed was a lack of discipline in Gerard Pique and Dani Alves and knew he had to change things - but didn't think he had had the strength to do it."
Roura criticised the choice of Alberto Undiano as referee for Tuesday's Copa del Rey Clasico, with the Pamplona-born official taking charge of the Catalans' only La Liga loss so far this season - January's 3-2 defeat to Real Sociedad, in which Pique was sent off.
Balague reckons Roura's outburst was an attempt to mask Barca's lack of swagger, something he says was clear in the defeat to Real, but he did praise Jose Mourinho's men for the way they contained their fellow Spanish heavyweights.
"Real Madrid looked like they had prepared their whole lives for this game, while Barcelona looked scared; if they thought they had the weapons to beat Real they wouldn't have complained about Undiano," said Balague.
"That showed they weren't confident and when the game started, Barcelona were very stretched; their defenders were too deep and the forwards did not have enough friends to pressure high - and Real took advantage of the spaces.
"(Cristiano) Ronaldo was one-on-one with a Barcelona centre-back many times and that was job well done for Real - and job very badly done from Barca. It shows they know how to play Barcelona - but what has lost them the league is that they do not know how to play teams like Granada."
Real Madrid and Barcelona will tangle again on Saturday in the second La Liga Clasico of the campaign. Catch all the action from 8pm on Sky Sports 1 HD.