Serena Williams' coach and rumored boyfriend, Patrick Mouratoglou, posted a picture she took of him on Tuesday, with a caption that jokingly complemented her photographic skills.

"@serenawilliams can't say if you are a great photographer but this one with chip & the flower behind is just amaz," he mentions in the tweet.

@serenawilliams can't say if you are a great photographer but this one with chip & the flower behind is just amaz. pic.twitter.com/74adxN9jQ4

— Patrick Mouratoglou (@pmouratoglou) July 16, 2013

Serena Williams and Patrick Mouratoglou are currently in Bastad where she will compete in the Collector Swedish Open.

She defeated Sesil Karatancheva of Kazakhstan 6-1, 6-2 in the first round on Tuesday.

But Serena Williams is also expected to face Andy Murray in a "Battle of the Sexes" challenge in what began as a Twitter joke, leaving tennis fans wondering who coach and rumored boyfriend Patrick Mouratoglou will root for.

Patrick Mouratoglou frequently tweets about Andy Murray, complimenting his performance in Wimbledon and his overall style in tennis, but is also a staunch supporter of Serena Williams and is speculated to be in a romantic relationship with her.

Williams suggested before she was dethroned as women's champion at Wimbledon that she would be prepared to take on Murray, who proposed Las Vegas as a potential location for any match between them, the Telegraph reports.

It is understood that several venues in Vegas would be interested in ­hosting what would be a re-enactment of two famous male-female tennis showdowns of the 1970s and one in the 1990s, the Telegraph also reports.