07/28/2012 05:14 EDT | Updated 09/27/2012 05:12 EDT

Raonic to unleash serve for Canada at the Olympics, Ito up first in singles

LONDON - Milos Raonic brings his booming serve back to the grass at Wimbledon on Sunday, this time competing for Canada as the 21-year-old from Thornhill, Ont., opens his Olympic tennis campaign.

Raonic, whose 609 aces trail only John Isner's 634 on the ATP Tour this year, is currently ranked 25th in the world. On Sunday, he meets 69th-ranked Tatsuma Ito of Japan in first-round Olympic play.

The six-foot-five right-hander has posted a 28-11 record this year and won tournaments at Chennai and San Jose. Ito is 7-9 in 2012.

The traditional all-white look that is synonymous with the historic All England Club will be abandoned for the Olympic tournament as players will be free to wear the colours of their national teams.

The ivy that clings to the walls throughout the venue is now in the shadow of large purple Olympic banners, which have given the storied grounds a look that will have Wimbledon fans doing a double-take at first glance.

Raonic lost in the second round in his last two appearances at the All England Club, suffering a hip injury two years ago that required surgery.

Also of note Sunday, Clara Hughes rides in the women's time trial, looking for a seventh Olympic medal. The 39-year-old won a pair of bronze medals in cycling at the 1996 Games before switching to speedskating and collecting a gold, one silver and two bronze.

"I'm excited to be here," Hughes said. "My ancestors are from here. I feel at home, being really pale and red hair. I feel really ordinary. I kind of like it."

Hughes, a native of Winnipeg who lives in Glen Sutton, Que., is currently tied with speedskater Cindy Klassen as Canada's most decorated Olympian.

"I think I'm a case study, honestly," Hughes said of her shift from speedskating back to cycling. "It's just fascinating how the body's composition can change, how the energy's system, the engine, can shift from being trained for several minutes of effort to being trained for a 140-kilometre road race. I found it fascinating."

The Canadian team also includes Joelle Numainville of Laval, Que., and Denise Ramsden of Yellowknife.

In rowing, the women's eight kicks off its run for gold with a heats race. The Canadian women lost to the Americans by just three hundreths of a second at a recent World Cup event in Lucerne.

Montreal's Emilie Heymans and Jennifer Abel of Laval, Que., compete in the women's synchronized three-metre springboard. They won silver at last year's world championship.

In swimming, Julia Wilkinson of Stratford, Ont., looks to advance to Monday's 100-metre backstroke final.

The beach volleyball team of Marie-Andree Lessard of Ville LaSalle, Que., and Annie Martin of Sherbooke, Que., opens against Britain.