What is the name of this retired professional tennis player and former World No. 1 who was the defending champion of the 2004 Siebel Open - Singles?
2004 Siebel Open – Singles Andre Agassi was the defending champion but lost in the semifinals to Mardy Fish.
Steve Siegel (tennis) Steve Siegel (born September 4, 1948) is a former professional tennis player from the United States.