Japan's Nishikori qualifies for ATP Tour finals in London

( Reuters) - Japan's Kei Nishikori will make a third straight appearance at the ATP Tour finals next month after becoming the fifth player to qualify for the season-ending tournament, organisers said on Wednesday.

The 26-year-old world number four will join the world's top three - Novak Djokovic, Andy Murray and Stanislas Wawrinka - plus big-serving sixth-ranked Canadian Milos Raonic in London, the ATP said in a statement.

Nishikori has had a strong year so far, having won his 11th Tour title at the Memphis Open and reached the Australian Open quarter-finals as well as the U.S. Open semi-finals.

Nishikori is currently nursing a muscle injury, which he sustained during the Japan Open in Tokyo last week, and was forced to sit out this week's Shanghai Masters.

(Reporting by Shravanth Vijayakumar in Bengaluru; Editing by Ken Ferris)