Three of the four world-famous participants in the third Heineken Stars contest in Ho Chi Minh City on Friday and Saturday have withdrawn due to injury.
The organizers said, on Monday, that they would be replaced with players at higher rankings in the world.
Only the 21st-ranked American player Sam Querrey remains unchanged. The other three stars 29th-ranked Argentine David Nalbandian, 113th-ranked American Robby Ginepri and 251st-ranked German Tommy Haas will not come.
The organizers have filled the vacancies with the 19th-ranked American Mardi Fish, 42nd-ranked Spaniard Tommy Robredo and 35th-ranked Argentine Juan Monaco.
Argentine Nalbandian suffered an injury when he and his national teammates clashed (unsuccessfully) with French players in the semi-finals of the Davis Cup earlier this month.
The American player Ginepri suffered an elbow injury during a recent training session in the U.S while Haas can't come due to a shoulder injury, according to the organizers.
The biennial contest's first edition in 2006 attracted Carlos Moya, Nicolas Kiefer, Rainer Schuettler and Juan Carlos Ferrero. The championship was won by Germany's Schuettler, currently ranked 90th.