Two -time world champion Alonso rejoins Button , the stable he left in one day . Alonso will be partnered by Jenson Button , retained above Ron Dennis . McLaren chairman McLaren labels the duo 'the best driver lineup ' of any F1 team . After plenty of uncertainty over whether Button or Magnussen would be retained for 2015 , McLaren chairman and CEO Ron Dennis is delighted with the pairing of two former world champions . rookie Kevin Magnussen will stay on as reserve and test driver .
Two -time world champion Alonso rejoins Button , the stable he left in one day . Alonso will be partnered by Jenson Button , retained above Ron Dennis . McLaren chairman McLaren labels the duo 'the best driver lineup ' of any F1 team . rookie Kevin Magnussen will stay on as reserve and test driver .