Switzerland's Roger Federer, right, chats with Cameron Norris, of Great Britain during a training session ahead of the Laver Cup tennis tournament at the O2 in London, Wednesday, Sept. 21, 2022. Federer appeared earlier at a news conference to discuss his retirement from professional tennis at age 41 after a series of knee operations. He will close his career with a doubles match at the Laver Cup on Friday. (AP Photo/Kin Cheung)