Complex sentence: After concentrating on the Champions Tour in 2006, Roberts went without a PGA Tour card for the 2007 and 2008 seasons, passing on using his exemption for being among the top 50 in career earnings.
Split into simpler sentences: After concentrating on the Champions Tour in 2006, Roberts lost his card. He did not use his 2007 season exemption option for being among the top 50 in career earnings.