Pedro de la Rosa says he had no qualms about leaving the McLaren team to race for BMW Sauber despite how respected he had become at the British squad.
De la Rosa is returning to racing this season after seven years as McLaren's test and reserve driver. The Spaniard last completed a full season with the Jaguar team back in 2002.
With current regulations limiting testing during the year, de la Rosa admits there was no point in being a test driver anymore, despite a solid job at McLaren.
"It was very clear for me from the beginning that I had to go back to racing, otherwise I would never go back racing, and especially with all the regulation changes," de la Rosa told reporters during the launch of the new BMW Sauber car.
"The fact that I was being a test driver who didn't drive the car very much during the year was very tough mentally for me, because I was not doing what I was born to. It was clear that I had to go back to racing. That was easy.
"After that, I have always been very honest with McLaren and McLaren has been very honest with me. I always kept them informed of what was the situation and that this could happen. That's life. I'm very grateful for what they have done for me and the reality is that I'm a more complete driver now and that's thanks to them. But we had to go back racing, we had to. With the current regulations there is no point in being a test driver anymore."
The 38-year-old, who last raced in Formula 1 in 2006, admitted he is very excited about being able to compete again.
"For me, it's obviously, I would say, my third comeback," he added. "First was when I started, second was with McLaren and now I'm back, so I'm extremely, extremely excited about this opportunity, not just because it's a comeback, but also because it's with a great team.
"I think it comes to me at a stage of my career where I'm mature enough to appreciate it and to exploit it. Because it is clear to me that if I have managed to get this race drive is because of the experience I have managed to accumulate with McLaren, so I'm very grateful to them that this has been possible. And apart from that I only promise work, motivation and that's it."
The Spaniard conceded it was hard to know what to expect from his new team this year, and reckons the picture will only be clear in the first race.
"You never know how quick the car is or not until you make it to Q1 in Bahrain. That's a typical answer but it's the reality. What I can detect as a driver is where are the biggest issues of the car or what the car needs to go faster. After that, it's just up to what the competitors' level is. You have to adjust against your competitors how good or bad you are."