Roger Federer prepares for a return against Andreas Seppi in the Shanghai Masters, October 9Reuters

Roger Federer announced his split with coach Paul Annacone as the 17-time Grand Slam champion looks for some way to resurrect his floundering career.

Federer, currently ranked just seven in the world, has struggled immensely in the Grand Slams this season, and bowed out in the second round of Wimbledon while trying to defend his title on the grass courts of the All-England club.

The Swiss great did not fare too well in the final Grand Slam of the year - the U.S. Open -- either, bowing out in the fourth round, before he was knocked out by Gael Monfils in the pre-quarterfinals of the Shanghai Masters, in his first tournament since that U.S. Open loss.

"After a terrific three and a half years working together, Paul and I have decided to move on to the next chapter in our professional lives," Federer wrote on www.rogerfederer.com.

"When we started together we had a vision of a three-year plan to win another Grand Slam title and get back to the number one ranking. Along with many other goals and great memories, these two main goals were achieved.

"After numerous conversations culminating at the end of our most recent training block, we felt like this was the best time and path for both of us.

"Paul remains a dear friend, and we both look forward to continuing our friendship. I want to thank Paul for his help and the value he has added to me and my team."

American Annacone, who famously coached Pete Sampras during the American great's halcyon days, took over as Federer's coach in August 2010, with the highlight during the duo's partnership being the 2012 Wimbledon title.