The ATP had already announced he would take part in the Brazil Open the following week.
"Rafael Nadal, considered by experts as the best claycourt tennis player of all time and one of the best in tennis history, has been confirmed for the Chile Open," organisers said on the claycourt tournament's website.
The Spanish former world number one has been sidelined with a knee injury since last year's Wimbledon tournament in June and his hopes of returning at the Australian Open were dashed by illness.
Nadal will play at the modest tournament in the Pacific coast city of Vina del Mar for the first time.
- Sports & Recreation
- Rafael Nadal
- Wimbledon tournament