Franz Tost has said that the points lost early in the season have cost Toro Rosso.
The team are currently struggling with a year-old Ferrari engine, but were contenders early in the year with points in nine of the first eleven races, but have only scored twice since as the rest of the field's engines continue to be developed and Toro Rosso Fall behind.
As a result, team boss Tost thinks that the points that the team did manage to lose early in the season are hindering them now.
"Step one was when Max Verstappen left for Red Bull Racing," he told the official F1 website. "That took away a lot of potential from the team. That does not mean that Daniil is not doing a fantastic job, but he had to recover. Then we had some engine failures that we didn’t expect."
“Next came our involvement in some incidents, like in Monaco when Carlos showed a real good performance and was in front of Perez before the pit stop - and after he had pitted he was nowhere - where clearly the team has lost his position," he added. "Then I always said that the second half of the season would be difficult, as there was no development on the engine - and now we are struggling with the pace. Now the points that we did not bag at the beginning of the season haunt us."
However, he did admit that challenging the top five would have been a task too much for the Italian team, although he did feel that targeting McLaren, who currently sit 19 points ahead of Toro Rosso, sixth in the constructors' standings, would have been a realistic ambition.
"To be fair, even if everything had worked perfectly for us this season Force India were simply too strong - and also Williams," Tost admitted. "But P6 should have been possible, because McLaren are not so far ahead of us."
Bahrain International Circuit - Winter testing