Rafael Nadal "not worried" about failure to retain Argentina Open title

Rafael Nadal has insisted that he is "not worried" about his form after failing to retain the Argentina Open title.

The Spaniard, who was knocked out of the Australian Open in the first round last month, arrived in South America as a wildcard.

Nadal reached the semi-final of the clay-court tournament, but could not progress any further as he suffered a 4-6 6-4 6-7 defeat to Dominic Thiem on Saturday.

"It was a tough match," BBC Sport quotes Nadal as saying. "I had a chance to win and missed it but Thiem played well.

"I'm not worried. I just lacked consistency and need to make fewer unforced errors, but that's nothing."

Thiem went on to win the Argentina Open title by beating Nicolas Almagro in the final on Sunday.