Carlos Sainz says Ferrari’s weaknesses came to the fore in the Spanish Grand Prix as he was unable to push to fight with the Mercedes and Red Bull drivers. The Spaniard started his home race from second on the grid and attacked Max Verstappen into Turn 1 but then faded as the race progressed, losing out to both Mercedes cars and then Sergio Perez late on. After his encouraging qualifying, Sainz says he knew what Ferrari’s limitations were going to be and he had to focus solely on looking after his tires. “I knew he was on a medium tire…