Jenson Button has revealed his regret that he and his colleagues were unable to celebrate Rubens Barrichello's retirement from F1.

The Brazilian has switched to IndyCar after being unable to secure an F1 seat this year, what would have been his twentieth season in the sport.

Button, who partnered the Brazilian for four seasons at Honda and Brawn, regrets the fact that he and his teammates were unable to celebrate Barrichello's long career.

"He is a friend and I worked with him for four years and I have a lot of respect for him," said the Englishman, when asked if he would miss Barrichello's presence in the paddock this tear. "I think we were all very disappointed that he wasn't going to be racing this year and also disappointed that Rubens decided to fight to race in F1 because we didn't get to have a big party at the end of the year in Brazil.

"But he is a racer and he still loves it," he continued. "He's nearly 40 years old and he's raced more GPs than anyone but he still wants to be racing and he's got the hunger still, and he's still quick. Setting up the car he's one of the best in the business.

"He's got his new career now in IndyCar which is brave after doing this for so long. But Rubens will be strong definitely."

Asked about Kimi Raikkonen's U-turn, which similarly follows Michael Schumacher's example of retiring from the sport and subsequently returning, Button said: "It just shows you that you shouldn't give up too early on the sport. There are obviously things in every job that you dislike, but we are doing one of the best jobs in the world and it proves with Michael leaving and coming back and Kimi leaving and coming back, that you have got to be careful when you leave and when you decide to retire.

"It's good to have him back," he added. "He's an interesting character and he's a great driver."