Barcelona manager Tata Martino "let himself down" in the club's second defeat of the week, Graham Hunter told Revista de La Liga.
A 1-0 loss to Granada on Saturday, which followed the club's Champions League exit to Atletico Madrid on Wednesday, was a hammer blow to Barcelona's title aspirations.
Despite an improved performance at the weekend, Barca again succumbed without troubling the scorers - and Hunter says manager Martino played his part.
"I think we have to evolve our learning and our understanding of what Martino is doing to either develop or hinder this latter part of the season, game by game," pundit Hunter explained.
"He let himself down, I think. It was clear that if they had so much possession and so many shots on target, all three substitutes should have been used.
"I think if you've got Xavi, who might open things up, or [Cristian] Tello who has shown the rare ability in this squad to shoot from distance and score [you should bring them on]."
Both players remained benched at the Estadio Nuevo Los Cármenes, however, Hunter took issue with Martino's decision to replace Sergio Busquets.
"If you choose to take off a player and you take off [Sergio] Busquets, who gives organisation and drive and can win the ball in the air from set-pieces, I find this strange," he said.
"In isolation you wouldn't pick on them but when you take the type of errors he's made in planning games, in reacting to defeats, in making substitutions, in motivating all throughout the season, I think you're beginning to find a man who's fit is not right with Barcelona as a squad or as a club or with their football philosophy right now."
But fellow Spanish football expert Guillem Balague insisted that Martino's players must take responsibility for their poor form.
"It was Neymar who was ineffective, it was [Lionel] Messi who was ineffective," he said. "They shot 29 times on goal and how can you coach that better?"
"The problem comes off the back of four other defeats in the league which hasn't happened since 2008. It comes off the back of another game in which they didn't score which hasn't happened since 2008.
"These are bad performances at the wrong time of the season."