Marat Safin has hired a new coach and fitness trainer after admitting he needs to get fitter if he is to reclaim his place in the top 10.
Safin is without a title since the 2005 Australian Open
The 27-year-old has split with Alexander Volkov and hired Gustavo Kuerten's former coach Hernan Gumy and fitness trainer Miguel Maseo.
"With a new coach I feel I can bring something more to my game," said Safin.
Former world number three David Nalbandian, now ranked 24, has hired Argentine Martin Jaite as his coach.
I know I can improve and I will do my very best to be there again
"I believe I need the extra help and experience that Martin has to try to lift my tennis back to the levels I reached at one time," said the 25-year-old Nalbandian.
Nalbandian, who has been without a coach since last year, and Safin both went out in the third round of Wimbledon.
Argentine Nalbandian, a former SW19 finalist, lost in straight sets to Marcos Baghdatis while Safin went down meekly to eventual champion Roger Federer.
Safin, a former world number one, is without a title since winning the 2005 Australian Open.
He was sidelined for six months with a knee injury but he has struggled to regain top form since returning to action in February 2006.
"I feel this summer is crucial for my career and I am determined to do something," said the Russian, whose first tournament of the US hardcourt season is the Countrywide Classic in Los Angeles from 16 July.
"I felt encouraged after my matches in Wimbledon and although I did not beat Roger, I did feel that I started to play better in the third set.
"Although I felt encouraged I also realised I need to do something with my game to make sure I get back where I want to be - in the top 10," he told his official website.
"I look forward to working with Hernan with his experience. I do not have a lot of points to defend this summer so I want to work hard and do well. My ranking is now 22 and my goal is to get higher.
"I know I can improve and I will do my very best to be there again."
Gumy has worked with Argentines Guillermo Canas and Guillermo Coria, as well as Brazilian Kuerten.
Safin's previous coaches include Mats Wilander, Peter Lundgren, Denis Golovanov and Marc Rosset.