Martin Brundle has said that Formula 1 drivers who have not been retained by their teams for the forthcoming season have had their chances to impress.
Bruno Senna, Kamui Kobayashi and Timo Glock are among the names that will be missing from the grid in 2013.
The former F1 driver, who now works as a commentator and pundit, told Sky Sports News: "It's sad isn't it, but it's the business. I've always said it's really hard to get to Formula 1 and it's even harder to stay there.
"They all had their chances to shine. Maybe that sounds a bit brutal, but they had their chances to shine. Just like when I got kicked out of F1, you had your chances, nothing else was there and it's about the fresh blood."
There will be five rookies racing in 2013, with Force India still to announce their second driver.
