McLaren has finally confirmed that Fernando Alonso and Jenson Button will be the team’s race drivers in 2015.
The news comes after weeks of speculation about whether Button or Kevin Magnussen would retain their race seats alongside the Spaniard.
Alonso and Button were team mates at Renault in 2002 when the former was reserve driver. He was promoted to a race seat for 2003, and Jenson moved to BAR.
Magnussen continues on the role of test and reserve driver and clearly still has the opportunity to bounce back to a race seat – although he faces strong competition from Stoffel Vandoorne.
Among those to have raced in F1, dropped into a test role and returned to have a successful career are Alonso, Mika Hakkinen and Felipe Massa.
Adam Cooper's F1 Blog 
It’s the right call, and Honda played a major role in this decision.
Ron Dennis had all three drivers over a barrel and drove a hard bargain, salary wise. The wait only benefited McLaren in any last minute negotiations, as each driver had nowhere else to go, if they wanted to stay in F1.
Say what you will about our man Ron, he didn’t get where he is by missing business opportunities when they are there to be had.