Federer needs one more major title to equal Sampras' record of 14. Sampras never managed to win the French Open before he retired. Federer hasn't won the Roland Garros title, either, leaving Wimbledon as the most likely opportunity for the Swiss to draw level with the American.

Federer's five-year winning streak at Wimbledon ended last year in an epic five-set final loss to Spaniard Rafael Nadal, who appears to have his measure in recent finals having also won in Paris last year and Australia in January. "It will be interesting for Rafa (Nadal) to come back as defending champion as before he was always just a contender, so there will be a bit more pressure on him this year," Sampras said of the looming Wimbledon tournament.

"Roger is very hungry for the title and he came so close last year. If I was to put my money on it, I would say Roger, but he's not a shoo-in." While Sampras was mulling over Federer's prospects, he was reliving his own past clashes with Agassi.

The two Americans will face off on Oct. 25 at the casino-hotel resort The Venetian Macao in the Chinese territory and gambling enclave. Praising Agassi's service return and passing shots, Sampras said in a telephone conference: "We always had really tough matches and we brought out the best in each other." When the duo were top and second-ranked men's players in the world in the mid-1990s, the rivalry "transcended the sport," Sampras said. "When people ask me who my great rival is I always tell them Andre."

Sampras won 64 singles titles, and Agassi took 60, including being the last man to win all four grand slam titles over his career.

In 34 meetings between the two, Sampras won 20, including the finals of the 1990, 1995 and 2002 U.S. Opens, plus Wimbledon in 1999. Agassi beat Sampras in the 1995 Australian Open final.