Former Ireland midfielder Ronnie Whelan believes Spain must seek a new solution up front if they are to turn around their fortunes in the World Cup.
Costa started as the main striker in the Spain side thrashed 5-1 by the Netherlands in last night’s Group B showdown.
The naturalised Spaniard, who played for Brazil in two friendly matches before choosing Spain, was one of the poorer performers as Vicente Del Bosque's side struggled to break down organised and energetic Dutch defence.
Spain took the lead through Xabi Alonso just before the half-hour mark but goals by Robin Van Persie (2), Arjen Robben (2) and Stefan de Vrij made it a miserable night for the current holders.
Spain could now meet Brazil in the next round, if they can secure second place in their pool.
Costa is due to move to Chelsea and Whelan believes manager Jose Mourinho should reconsider if he has that option.
Speaking on the RTÉ panel after the match, Whelan said: "If I was Mourinho now, if the deal had not gone through, I’d be thinking about it seriously. Costa is big and strong but I don’t think he will really frighten top centre-backs. If I was a centre-back myself I don’t think I would be particularly worried."
Whelan’s fellow analyst Liam Brady added: "He is awkward and he doesn’t seem to fit into that Spanish team. Spain are depending on neat little passes all the time, there is no variation. You need pace in the team. Diego Costa has power but he does not have blistering pace."
Costa’s indifferent performance was not the only talking point on the night. The striker appeared to clash with Bruno Martins, and the Dutch defender made clear afterwards that he felt he had been the victim of a head-butt.
Former Ireland striker Richie Sadlier commented: “The most disappointing aspect of his performance was that he appeared to head-butt one of the Dutch defenders at a time when the game was lost. So there is a questionable temperament as well."