Henman slipped down the latest rankings released yesterday, following his second-round exit in last week's Stockholm Open. The British No1 falls two places to 12, while the injured Rusedski drops to 14 after sliding from sixth to 12th last week.
Both players have come to the end of their seasons having failed to qualify for next week's ATP Tour World Championship in Hanover.
Britain have had at least one representative in the top 10 since October 1998 and both players will begin next season outside the top group. Sweden's Thomas Enqvist rises to No 4 after his win in Stockholm.
In New York today, Martina Hingis will begin her defence of the Chase Championships determined the change things having lost her last two tournaments. "You want to end up the season with a victory," she said before the action began at Madison Square Garden.
Hingis is ranked No 1 and is the top seed in the 16-player field. Lindsay Davenport, seeded No 2, lost to Hingis in this event last year but she beat the Swiss teenager 6-3, 6-4 on Sunday to capture the Advanta Championships in Philadelphia for the first time.
Hingis also lost a final in Zurich to Venus Williams, one of four players making their debut in the season-ending showcase. The others are the younger Williams sister, Serena, along with Amelie Mauresmo, of France and Barbara Schett, of Austria.
Three of the sport's biggest names of recent years, however, will be missing. Steffi Graf, who won the title five times, has retired and will be honoured by Madison Square Garden and the WTA Tour tonight. The ceremony will be held after the first singles match of the evening.
"Steffi's retirement never gave her fans a chance to say goodbye," said Jim Fuhse, WTA Tour director of promotions. "Tonight will give them their chance."
Rankings, Digest, page 31