Ron Dennis says Kevin Magnussen was dropped by McLaren because he did not achieve the goals the team had set for him.
In October Magnussen confirmed his split from McLaren, where he had been a reserve driver. He drove for the team in 2014 and scored a podium on his debut in Melbourne but was dropped at the end of the year when McLaren opted to retain Jenson Button alongside Fernando Alonso.
Magnussen deputised for the injured Alonso at this year's Australian Grand Prix but did not start the race as his Honda engine failed on the way to the grid. After failing to land a drive away from F1 Magnussen spent the rest of the year on the sidelines.
McLaren CEO Dennis says the Danish driver knows he did not live up to expectations.
"He was given every opportunity, a season in Formula One followed by very clear goals that he had to achieve in 2014 and he didn't achieve those goals," Dennis said. "He knows himself and, no question, he knew that he didn't perform as he should have done this season."
Magnussen's hopes of a Formula One seat in 2016 now hinge with Manor, which is yet to confirm its line-up for next year. However, he has recently tested Porsche's Le Mans-winning LMP1 car and is set to test for Mercedes in DTM.
Dennis insists Magnussen has the talent to be a success in Formula One and says there the team will continue to monitor his career from this point on.
"He is a good, talented driver, more than capable of driving in Formula One. But there are several drivers capable of driving in Formula One, who for one reason or another don't get that opportunity. Both he and all drivers that come to McLaren and leave McLaren always get continuous support if they want to receive it. We don't walk away from our drivers and we're always supportive of our drivers.
"Some that have left under a little bit of a dark cloud -- so there's the exception to the rule -- but basically we do a great deal to bring young drivers on. We care. We take these young people and we pay for their careers: we paid for Kevin's career, we paid for Lewis [Hamilton]'s career; people forget we paid for [Nico] Rosberg's career in the early days."