Nadal's uncle says Rafa's ailing left knee may bother him for a few more weeks

VINA DEL MAR, Chile – Rafael Nadal's injured left knee is getting better, although his coach, uncle Toni Nadal, says it may bother him for a few more weeks.

Nadal practiced Monday for 90 minutes with Chilean Nicolas Massu, his fourth straight day of training since arriving in Chile for his first match in more than seven months.

The seven-time French Open champion opens up Tuesday in the VTR Open, playing doubles with Argentine Juan Monaco. On Wednesday, he's got a second-round singles match against a qualifier or Argentine Guido Pella.

Nadal is the game's best clay-court player and will be a prohibitive favorite to win a title here against a relatively weak field.