Defending champion Novak Djokovic says "it will be the duel of the veterans of the tour" when he faces old rival Stan Wawrinka at Wimbledon on Friday.
Wawrinka, 38, has twice beaten Djokovic in Grand Slam finals but says he "doesn't really stand a chance".
Andy Murray, 36, will finish his second-round match with 24-year-old fifth seed Stefanos Tsitsipas, with the Briton leading by two sets to one.
Carlos Alcaraz, Iga Swiatek, Ons Jabeur and Cameron Norrie are also in action.
One of the highlights of the day could well be the third-round meeting between three-time Grand Slam winner Wawrinka against 36-year-old Djokovic, who clinched his 23rd major at the French Open last month.
Two of Wawrinka's Slams have come against Djokovic - the 2015 French Open final and the 2016 US Open final - and the Serb has not forgotten.
Asked what role 88th-ranked Wawrinka has played in his career, a laughing Djokovic, 36, said: "Well, he took away two Grand Slams from me.
"No, I like Stan a lot. He's a great person and really inspirational what he's doing at his age. He's almost 40 and he still keeps going strong, that's something not many people can do.
"We can't forget he's a three-time Grand Slam champion, Davis Cup winner and also Olympic gold. He's had a fantastic career.
"We haven't faced in quite some time. It will be the duel of the veterans of the tour."
