Japan's Kei Nishikori says left calf 'feeling pretty well' as he returns to tour in Washington

Kei Nishikori says his injured left calf is healed after taking time off following Wimbledon.

Japan's Nishikori is seeded No. 2 at the Citi Open hard-court tournament and, after a first-round bye, he will face Australia's James Duckworth in the second round on Tuesday.

Nishikori, the runner-up at the U.S. Open in 2014, said Monday he is "feeling pretty well, actually" and that his leg is fine thanks to a week of rest after his early exit at the All England Club in early July.

He withdrew before his second-round match at Wimbledon, citing a lingering problem with the calf. The Citi Open marks his first tournament since then.

Duckworth advanced Monday by beating Ryan Harrison of the United States 6-1, 7-6 (4).