MELBOURNE, Australia — One thousand tennis matches. In a career full of major milestones, here comes another for Roger Federer, who will hit quadruple digits when he hits his first ball against Juan Martín del Potro in their Australian Open quarterfinal on Tuesday.

Federer has, of course, played a lot more matches than 1,000 if you count his junior and satellite days, but he played his first tour-level match in Gstaad, Switzerland, in 1998, losing to the Argentine player Lucas Arnold.

Nearly 14 years later, Federer is the most successful player of the Open era, with a record 16 Grand Slam singles titles. Asked tongue-in-cheek by an Italian journalist Sunday if he could tell him something about each of his past matches, Federer cracked a grin and declined.

“It’s been a lot of matches, and I remember some very vividly,” he said. “Some I’ve started to forget, which I guess is a good sign.”