The 2015 Grand Slam season begins Monday with multiple major winners Roger Federer, Rafael Nadal, Andy Murray and Maria Sharapova gracing the Melbourne Park courts on the opening day of the Australian Open.

The weather forecast for Monday is a comfortable 24 Celsius (75 Fahrenheit) with temperatures not expected to vary significantly for much of the first week, with light rain possible on some days.

None of those 40C (104F) scorchers in the forecast — yet.

Here are a few things to watch on Monday:

PESSIMISTIC NADAL: Rafael Nadal, who is coming back from a right wrist injury and recovering from appendix surgery in November, didn't need a tough first-round match, but he drew one in former top-10 player Mikhail Youzhny. Nadal has beaten the Russian in 11 of 15 matches, but one of Youzhny's wins came in the quarterfinals of the U.S. Open in 2006. Nadal, who has won their last five matches, said he'll be happy to win a few rounds at Melbourne Park because he's not feeling match-fit. "I don't consider myself one of the favorites here," the No. 3-ranked Nadal said at a pre-tournament news conference. "I would be lying if I say I feel that I am ready to win." Nadal is the third match on Rod Laver Arena during the day session.

___

FEDERER BEGINS QUEST FOR 18: Roger Federer hasn't added to his tally of Grand Slam singles titles since he won his 17th at Wimbledon in 2012, but the 33-year-old Swiss star made great strides toward another major last year, making the semifinals here and at the U.S. Open as well as losing to Novak Djokovic in the Wimbledon final. He opens the night session on Rod Laver Arena against Taiwan's Lu Yen-hsun, whom he has beaten in all three previous meetings. "I would hope that over the years I've always improved," Federer says. "I think I'm serving more consistent and stronger than I ever have. But I'm definitely very pleased how things have gone now the last six months."

___

MARIA TO FOLLOW: Maria Sharapova plays qualifier Petra Martic of Czech Republic in the final match of the night at Rod Laver Arena, hoping she'll be able to improve on her 2014 appearance here when she lost in the fourth round. She went all the way in her next Grand Slam, winning the French Open for the second time to increase her career major titles to five. The 2008 Australian Open winner won the Brisbane International in her only tune-up tournament, beating Ana Ivanovic, but isn't placing a lot of emphasis on that victory. "You can't be overly negative; you can't be overly positive," Sharapova says. "I wanted to start off well. I thought I did many things well. But I'm not going into next week throwing flowers at myself or anything." Sharapova has a chance to return to No. 1, supplanting Serena Williams, after the Australian Open this year, but needs to at least advance to the final.

___

NEW YEAR, NEW ROOF: Andy Murray plays Indian qualifier Yuki Bhambri and Canadian Eugenie Bouchard takes on Anna-Lena Friedsam of Germany among five matches to officially open the refurbished Margaret Court Arena and its new retractable roof, the third covered venue at Melbourne Park. Seating capacity has also been increased to 7,500. The last match will see 19-year-old Nick Kyrgios of Australia play Federico Delbonis of Argentina. Kyrgios was as wild-card entry at Wimbledon last year when he stunned then No. 1-ranked Nadal in the fourth round, hitting a career-high 47 aces, the most Nadal had ever faced. But the shot everyone remembers is the between-the-legs effort from the back of the court by Krygios that dropped over the net and which Nadal didn't even bother to make a move to return. Krygios is fighting a back injury and he admits he would't be playing if it wasn't his home Grand Slam. "I think I'm putting a bit more expectation and pressure on myself as well to perform, and obviously I'm expecting more out of myself now," the Australian said.

____

TOP SEEDS, CHAMPS IDLE OR RETIRED: With the bottom half of both draws playing Monday, both top seeds — Novak Djokovic and Serena Williams — won't play until Tuesday. As well, neither of the defending champions will see action — 2014 women's winner Li Na retired in September, and last year's men's winner, Stan Wawrinka, plays Marsel Ilhan of Turkey on Tuesday.