Christian Horner says the next three races will be among Red Bull's toughest of the year, but is still confident his team can return to form in the second half of the season.
While Mercedes and Ferrari have battled for wins in the opening six rounds of 2017, Red Bull has been off the pace since testing pre-season testing and has scored just three podiums this year. It made a step forward with an aerodynamic upgrade in Spain -- which also helped on the tight streets of Monaco -- but a Renault engine upgrade for the Canadian Grand Prix has been delayed.