Carlos Sainz says he has been impressed with the progress being made by McLaren-Honda.
After a shocking 2015, the new Anglo-Japanese collaboration has been making gradual progress this year and has arrived at Spa with a new Honda engine that will benefit from a full 7 tokens of performance upgrades.
"They are almost the fourth car already and if their development works, they could be the surprise of the end of the season," Toro Rosso driver Sainz said.
"Great news for him and bad for us," the Spaniard, referring to his countryman and friend Fernando Alonso, is quoted by the Spanish daily Marca.
Indeed, McLaren is seventh in the constructors’ championship but just 3 points behind Toro Rosso. Losing sixth would cost "important money for Toro Rosso", Sainz admitted.