Three things to watch out for at the French Open on Monday

PARIS (Reuters) - Three things to watch out for on day nine of the French Open on Monday. * Keep your guard up, Andy World number one Andy Murray will need to keep his guard up when he takes on 21-year-old Karen Khachanov for a spot in the last eight with the Russian having already caused two upsets in Paris so far. Khachanov, ranked 53rd in the world, eliminated 13th seed Tomas Berdych in round two before beating big-serving John Isner, seeded 21st, in four sets. * Will they shake hands ? Not on speaking terms over a Fed Cup-related controversy, Caroline Garcia and Alize Cornet take their differences to court in the fourth round on Philippe Chatrier. Regardless of the result, two French women will be in the quarter-finals as Kristina Mladenovic booked her spot on Sunday. The question is: Will the pair shake hands? * Martic looking to join select club of quali-flyers If Croatia's Petra Martic beats Ukraine's Elina Svitolina, the fifth seed, she will become the first qualifier in the women's draw to reach the last eight since Yaroslava Shvedova in 2011, and the ninth since tennis turned professional in 1968. None of them made it to the semi-finals. (Reporting by Julien Pretot and Karolos Grohmann; Editing by Rex Gowar)