Carlos Sainz says McLaren is aiming for success only in the medium to long term.
The Spaniard says he is happy to move from the works Renault team to McLaren, the beleaguered yet once-great British outfit, on a new two-year contract.
Sainz said his countryman Fernando Alonso advised him to sign, because it is "a team with potential to succeed in the medium term".
"For me it was a positive year," he is quoted by EFE news agency. "It gave me the opportunity to open a door like McLaren for the next two years and I'm sure I'll enjoy them.
"I'm excited. That's the word to describe how I feel," said Sainz.
"In this month I was able to go to the factory to meet the people and see a team that has had such a hard year but now has a renewed spirit," the 24-year-old added.
But he said the "realistic" aim for now is that the Woking team improves "little by little".
"I do not know how much we will improve, but I hope to see progress and contribute as much as possible," said Sainz.
"The short term is important, but we cannot forget that it is a medium term project. The really important thing is where we will be two years from now, not so much in Australia next year.
"Fernando advised me to go to McLaren as he believes the team has potential. He knows that the project is medium or long term, but I am young enough to have patience and establish myself in a team like this," he added.
