Tennis competition extravaganza Wimbledon started in the UK yesterday and no doubt marketers are jumping over themselves to get the biggest tennis stars on board to promote their brand.

Recognising the desire many marketers and brands have for being associated with a sports champion, Adobe has released its Adobe Digital Index (ADI), measuring the social clout scores – a score determining the power of someone on social media – of various tennis athletes.

Topping the list was Serbia’s Novak Djokovic with his social media sphere consisting of more than 10 million followers and fans, the most number of mentions in the last 30 days and the highest international reach.

Second was Amercia’s Serena Williams with 8.7 million fans across social media platforms. While she had the largest number of Instagram followers, her social media mentions weren’t up to Djokovic’s level.

Check out the slideshow below for the full list of ten.

“The composite index of social clout clearly demonstrates that there are many angles to consider when selecting an athlete for a marketing sponsorship,” said Tamara Gaffney, principal analyst at ADI. “Marketers should look at sentiment, international reach, overall fan base and different leadership positions by network to select the best possible fit. Tennis very may well be the best place to find female athletes for product endorsements.”

“We’re finding that victory can certainly boost the social presence of an athlete,” said Joe Martin, an analyst at ADI.  “Marketers should be looking at social clout when considering athletic sponsorships and work with athletes to activate their social clout.”