Retired: Colt Knost, from the PGA Tour, after he missed the cut last week at the Waste Management Phoenix Open, GolfChannel.com’s Will Gray reported. Knost, 34, who was competing on a major medical extension after recovering from surgery on his left wrist, needed to win the tournament to retain his playing privileges. He shot 70-72 at TPC Scottsdale to miss the 36-hole cut by one stroke. Knost, who lives in Scottsdale, co-hosts a golf show on SiriusXM satellite radio and recently accepted a position with CBS Sports. Fans of amateur golf will remember Knost and the summer of 2007, when he won the U.S. Amateur Public Links and U.S. Amateur titles en route to the No. 1 amateur ranking in the world. Knost, a SMU graduate, went 2-0-2 for the winning U.S. Walker Cup team in 2007. He turned pro that fall and won twice on what was then the Nationwide Tour in 2008, earning a promotion to the PGA Tour. Knost never won in 199 starts on the PGA Tour, finishing as high as third and amassing $4.33 million in earnings.